diff --git a/rodbus/examples/custom_server.rs b/rodbus/examples/custom_server.rs
index 899e43df..43d52292 100644
--- a/rodbus/examples/custom_server.rs
+++ b/rodbus/examples/custom_server.rs
@@ -78,7 +78,7 @@ impl RequestHandler for SimpleHandler {
         }
     }
 
-    fn process_cfc_69(&mut self, values: &CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_69(&mut self, values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
         tracing::info!("processing custom function code: {}", values.function_code());
         // increment each CFC value by 1 and return the result
         // Create a new vector to hold the incremented values
diff --git a/rodbus/src/client/channel.rs b/rodbus/src/client/channel.rs
index c47f5bf8..5509f412 100644
--- a/rodbus/src/client/channel.rs
+++ b/rodbus/src/client/channel.rs
@@ -169,8 +169,8 @@ impl Channel {
     pub async fn send_custom_function_code(
         &mut self,
         param: RequestParam,
-        request: CustomFunctionCode<u16>,
-    ) -> Result<CustomFunctionCode<u16>, RequestError> {
+        request: CustomFunctionCode,
+    ) -> Result<CustomFunctionCode, RequestError> {
         let (tx, rx) = tokio::sync::oneshot::channel::<Result<CustomFunctionCode<u16>, RequestError>>();
         let request = wrap(
             param,
diff --git a/rodbus/src/client/message.rs b/rodbus/src/client/message.rs
index 91ac61d2..43ef934b 100644
--- a/rodbus/src/client/message.rs
+++ b/rodbus/src/client/message.rs
@@ -46,7 +46,7 @@ pub(crate) enum RequestDetails {
     WriteSingleRegister(SingleWrite<Indexed<u16>>),
     WriteMultipleCoils(MultipleWriteRequest<bool>),
     WriteMultipleRegisters(MultipleWriteRequest<u16>),
-    SendCustomFunctionCode(CustomFCRequest<CustomFunctionCode<u16>>),
+    SendCustomFunctionCode(CustomFCRequest<CustomFunctionCode>),
 }
 
 impl Request {
diff --git a/rodbus/src/client/requests/send_custom_fc.rs b/rodbus/src/client/requests/send_custom_fc.rs
index c51aa22e..50ef9d45 100644
--- a/rodbus/src/client/requests/send_custom_fc.rs
+++ b/rodbus/src/client/requests/send_custom_fc.rs
@@ -66,7 +66,7 @@ where
     }
 }
 
-impl CustomFCOperation for CustomFunctionCode<u16> {
+impl CustomFCOperation for CustomFunctionCode {
     fn serialize(&self, cursor: &mut WriteCursor) -> Result<(), RequestError> {
         cursor.write_u8(self.function_code())?;
 
diff --git a/rodbus/src/common/parse.rs b/rodbus/src/common/parse.rs
index 89baa648..c8a69712 100644
--- a/rodbus/src/common/parse.rs
+++ b/rodbus/src/common/parse.rs
@@ -28,7 +28,7 @@ impl Parse for Indexed<u16> {
     }
 }
 
-impl Parse for CustomFunctionCode<u16> {
+impl Parse for CustomFunctionCode {
     fn parse(cursor: &mut ReadCursor) -> Result<Self, RequestError> {
         let fc = cursor.read_u8()?;
         let len = cursor.remaining() / 2;
diff --git a/rodbus/src/common/serialize.rs b/rodbus/src/common/serialize.rs
index c7572d13..8da1530c 100644
--- a/rodbus/src/common/serialize.rs
+++ b/rodbus/src/common/serialize.rs
@@ -290,7 +290,7 @@ impl Serialize for WriteMultiple<u16> {
     }
 }
 
-impl Serialize for &CustomFunctionCode<u16> {
+impl Serialize for CustomFunctionCode {
     fn serialize(&self, cursor: &mut WriteCursor) -> Result<(), RequestError> {
         cursor.write_u8(self.function_code())?;
 
@@ -301,7 +301,7 @@ impl Serialize for &CustomFunctionCode<u16> {
     }
 }
 
-impl Loggable for &CustomFunctionCode<u16> {
+impl Loggable for CustomFunctionCode {
     fn log(
         &self,
         payload: &[u8],
@@ -353,7 +353,7 @@ mod tests {
 
     #[test]
     fn serialize_succeeds_for_valid_cfc_of_single_min_value() {
-        let custom_fc = &CustomFunctionCode::new(1, vec![0x0000]);
+        let custom_fc = CustomFunctionCode::new(1, vec![0x0000]);
         let mut buffer = [0u8; 4];
         let mut cursor = WriteCursor::new(&mut buffer);
         custom_fc.serialize(&mut cursor).unwrap();
@@ -362,7 +362,7 @@ mod tests {
 
     #[test]
     fn serialize_succeeds_for_valid_cfc_of_single_max_value() {
-        let custom_fc = &CustomFunctionCode::new(1, vec![0xFFFF]);
+        let custom_fc = CustomFunctionCode::new(1, vec![0xFFFF]);
         let mut buffer = [0u8; 4];
         let mut cursor = WriteCursor::new(&mut buffer);
         custom_fc.serialize(&mut cursor).unwrap();
@@ -371,7 +371,7 @@ mod tests {
 
     #[test]
     fn serialize_succeeds_for_valid_cfc_of_multiple_min_values() {
-        let custom_fc = &CustomFunctionCode::new(3, vec![0x0000, 0x0000, 0x0000]);
+        let custom_fc = CustomFunctionCode::new(3, vec![0x0000, 0x0000, 0x0000]);
         let mut buffer = [0u8; 8];
         let mut cursor = WriteCursor::new(&mut buffer);
         custom_fc.serialize(&mut cursor).unwrap();
@@ -380,7 +380,7 @@ mod tests {
 
     #[test]
     fn serialize_succeeds_for_valid_cfc_of_multiple_max_values() {
-        let custom_fc = &CustomFunctionCode::new(3, vec![0xFFFF, 0xFFFF, 0xFFFF]);
+        let custom_fc = CustomFunctionCode::new(3, vec![0xFFFF, 0xFFFF, 0xFFFF]);
         let mut buffer = [0u8; 8];
         let mut cursor = WriteCursor::new(&mut buffer);
         custom_fc.serialize(&mut cursor).unwrap();
diff --git a/rodbus/src/server/handler.rs b/rodbus/src/server/handler.rs
index 338eb570..772b7a32 100644
--- a/rodbus/src/server/handler.rs
+++ b/rodbus/src/server/handler.rs
@@ -64,97 +64,97 @@ pub trait RequestHandler: Send + 'static {
     }
 
     /// Write the CFC65 custom function code
-    fn process_cfc_65(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_65(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC66 custom function code
-    fn process_cfc_66(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_66(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC67 custom function code
-    fn process_cfc_67(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_67(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC68 custom function code
-    fn process_cfc_68(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_68(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC69 custom function code
-    fn process_cfc_69(&mut self, _values: &CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_69(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC70 custom function code
-    fn process_cfc_70(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_70(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC71 custom function code
-    fn process_cfc_71(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_71(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC72 custom function code
-    fn process_cfc_72(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_72(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC100 custom function code
-    fn process_cfc_100(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_100(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC7101 custom function code
-    fn process_cfc_101(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_101(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC102 custom function code
-    fn process_cfc_102(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_102(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC103 custom function code
-    fn process_cfc_103(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_103(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC104 custom function code
-    fn process_cfc_104(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_104(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC105 custom function code
-    fn process_cfc_105(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_105(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC106 custom function code
-    fn process_cfc_106(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_106(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC107 custom function code
-    fn process_cfc_107(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_107(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC108 custom function code
-    fn process_cfc_108(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_108(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC109 custom function code
-    fn process_cfc_109(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_109(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 
     /// Write the CFC110 custom function code
-    fn process_cfc_110(&mut self, _values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_110(&mut self, _values: CustomFunctionCode) -> Result<CustomFunctionCode, ExceptionCode> {
         Err(ExceptionCode::IllegalFunction)
     }
 }
@@ -323,97 +323,97 @@ pub trait AuthorizationHandler: Send + Sync + 'static {
     }
 
     /// Authorize a Send CFC65 request
-    fn process_cfc_65(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_65(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC66 request
-    fn process_cfc_66(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_66(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC67 request
-    fn process_cfc_67(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_67(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC68 request
-    fn process_cfc_68(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_68(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC69 request
-    fn process_cfc_69(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_69(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC70 request
-    fn process_cfc_70(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_70(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC71 request
-    fn process_cfc_71(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_71(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC72 request
-    fn process_cfc_72(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_72(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC100 request
-    fn process_cfc_100(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_100(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC101 request
-    fn process_cfc_101(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_101(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC102 request
-    fn process_cfc_102(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_102(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC103 request
-    fn process_cfc_103(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_103(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC104 request
-    fn process_cfc_104(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_104(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC105 request
-    fn process_cfc_105(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_105(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC106 request
-    fn process_cfc_106(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_106(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC107 request
-    fn process_cfc_107(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_107(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC108 request
-    fn process_cfc_108(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_108(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC109 request
-    fn process_cfc_109(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_109(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 
     /// Authorize a Send CFC110 request
-    fn process_cfc_110(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_110(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Deny
     }
 }
@@ -496,97 +496,97 @@ impl AuthorizationHandler for ReadOnlyAuthorizationHandler {
     }
 
     /// Authorize a Send CFC65 request
-    fn process_cfc_65(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_65(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC66 request
-    fn process_cfc_66(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_66(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC67 request
-    fn process_cfc_67(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_67(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC68 request
-    fn process_cfc_68(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_68(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC69 request
-    fn process_cfc_69(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_69(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC70 request
-    fn process_cfc_70(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_70(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC71 request
-    fn process_cfc_71(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_71(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC72 request
-    fn process_cfc_72(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_72(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC100 request
-    fn process_cfc_100(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_100(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC101 request
-    fn process_cfc_101(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_101(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC102 request
-    fn process_cfc_102(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_102(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC103 request
-    fn process_cfc_103(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_103(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC104 request
-    fn process_cfc_104(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_104(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC105 request
-    fn process_cfc_105(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_105(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC106 request
-    fn process_cfc_106(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_106(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC107 request
-    fn process_cfc_107(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_107(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC108 request
-    fn process_cfc_108(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_108(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC109 request
-    fn process_cfc_109(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_109(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 
     /// Authorize a Send CFC110 request
-    fn process_cfc_110(&self, _unit_id: UnitId, _value: CustomFunctionCode<u16>, _role: &str) -> Authorization {
+    fn process_cfc_110(&self, _unit_id: UnitId, _value: CustomFunctionCode, _role: &str) -> Authorization {
         Authorization::Allow
     }
 }
@@ -624,7 +624,7 @@ mod tests {
         );
 
         assert_eq!(
-            handler.process_cfc_69(&CustomFunctionCode::new(0x45, vec![0x01, 0x02, 0x03, 0x04])),
+            handler.process_cfc_69(CustomFunctionCode::new(0x45, vec![0x01, 0x02, 0x03, 0x04])),
             Err(ExceptionCode::IllegalFunction)
         );
         assert_eq!(
diff --git a/rodbus/src/server/request.rs b/rodbus/src/server/request.rs
index 8ae90405..3bb53772 100644
--- a/rodbus/src/server/request.rs
+++ b/rodbus/src/server/request.rs
@@ -21,7 +21,7 @@ pub(crate) enum Request<'a> {
     WriteSingleRegister(Indexed<u16>),
     WriteMultipleCoils(WriteCoils<'a>),
     WriteMultipleRegisters(WriteRegisters<'a>),
-    SendCustomFunctionCode(CustomFunctionCode<u16>),
+    SendCustomFunctionCode(CustomFunctionCode),
 }
 
 /// All requests that support broadcast
diff --git a/rodbus/src/types.rs b/rodbus/src/types.rs
index 42706202..d230bf8c 100644
--- a/rodbus/src/types.rs
+++ b/rodbus/src/types.rs
@@ -86,10 +86,10 @@ pub(crate) struct RegisterIteratorDisplay<'a> {
 }
 
 /// Custom Function Code
-#[derive(Clone, Debug, PartialEq)]
-pub struct CustomFunctionCode<T> {
+#[derive(Clone, Debug, Copy, PartialEq)]
+pub struct CustomFunctionCode{
     fc: u8,
-    data: Vec<T>,
+    data: Vec<u16>,
 }
 
 impl std::fmt::Display for UnitId {
@@ -374,7 +374,7 @@ impl Default for UnitId {
     }
 }
 
-impl CustomFunctionCode<u16> {
+impl CustomFunctionCode {
     /// Create a new custom function code
     pub fn new(fc: u8, data: Vec<u16>) -> Self {
         Self { fc, data }
@@ -396,7 +396,7 @@ impl CustomFunctionCode<u16> {
     }
 }
 
-impl std::fmt::Display for CustomFunctionCode<u16> {
+impl std::fmt::Display for CustomFunctionCode {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "values: [")?;
         for (i, val) in self.data.iter().enumerate() {
diff --git a/rodbus/tests/integration_test.rs b/rodbus/tests/integration_test.rs
index 3260451f..a79c898d 100644
--- a/rodbus/tests/integration_test.rs
+++ b/rodbus/tests/integration_test.rs
@@ -95,7 +95,7 @@ impl RequestHandler for Handler {
         Ok(())
     }
 
-    fn process_cfc_69(&mut self, values: &CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
+    fn process_cfc_69(&mut self, values: CustomFunctionCode<u16>) -> Result<CustomFunctionCode<u16>, ExceptionCode> {
         tracing::info!("processing custom function code: {}, data: {:?}", values.function_code(), values.iter());
         // increment each CFC value by 1 and return the result
         let incremented_values = values.iter().map(|&x| x + 1).collect();