diff --git a/doc/metric_spec.md b/doc/metric_spec.md
index 6c9fdad..ea033db 100644
--- a/doc/metric_spec.md
+++ b/doc/metric_spec.md
@@ -173,7 +173,7 @@ The DRBD subsystems collect devices stats by parsing its configuration the JSON
 0. [Sample](../test/drbd.metrics)
 1. [`ha_cluster_drbd_resources`](#ha_cluster_drbd_resources)
 2. [`ha_cluster_drbd_connections`](#ha_cluster_drbd_connections)
-
+3. [`ha_cluster_drbd_connections_sync`](#ha_cluster_drbd_connections_sync`)
 
 ### `ha_cluster_drbd_connections`
 
@@ -192,6 +192,11 @@ Either the value is `1`, or the line is absent altogether.
 
 The total number of lines for this metric will be the cardinality of `resource` times the cardinality of `peer_node_id`.
 
+### `ha_cluster_drbd_connections_sync`
+
+#### Descriptions
+
+The DRBD disk connections in sync percentage. Values from 0 to 100.
 
 ### `ha_cluster_drbd_resources`
 
diff --git a/drbd_metrics.go b/drbd_metrics.go
index ede1c77..e474b7d 100644
--- a/drbd_metrics.go
+++ b/drbd_metrics.go
@@ -26,6 +26,7 @@ type drbdStatus struct {
 		PeerDevices []struct {
 			Volume        int    `json:"volume"`
 			PeerDiskState string `json:"peer-disk-state"`
+			PercentInSync int    `json:"percent-in-sync"`
 		} `json:"peer_devices"`
 	} `json:"connections"`
 }
@@ -34,8 +35,9 @@ var (
 	drbdMetrics = metricDescriptors{
 		// the map key will function as an identifier of the metric throughout the rest of the code;
 		// it is arbitrary, but by convention we use the actual metric name
-		"resources":   NewMetricDesc("drbd", "resources", "The DRBD resources; 1 line per name, per volume", []string{"name", "role", "volume", "disk_state"}),
-		"connections": NewMetricDesc("drbd", "connections", "The DRBD resource connections; 1 line per per resource, per peer_node_id", []string{"resource", "peer_node_id", "peer_role", "volume", "peer_disk_state"}),
+		"resources":        NewMetricDesc("drbd", "resources", "The DRBD resources; 1 line per name, per volume", []string{"name", "role", "volume", "disk_state"}),
+		"connections":      NewMetricDesc("drbd", "connections", "The DRBD resource connections; 1 line per per resource, per peer_node_id", []string{"resource", "peer_node_id", "peer_role", "volume", "peer_disk_state"}),
+		"connections_sync": NewMetricDesc("drbd", "connections_sync", "The in sync percentage value for DRBD resource connections", []string{"resource", "peer_node_id", "volume"}),
 	}
 	drbdsetupPath = "/usr/sbin/drbdsetup"
 )
@@ -94,7 +96,11 @@ func (c *drbdCollector) Collect(ch chan<- prometheus.Metric) {
 				continue
 			}
 			for _, peerDev := range conn.PeerDevices {
-				ch <- c.makeGaugeMetric("connections", float64(1), resource.Name, strconv.Itoa(conn.PeerNodeID), conn.PeerRole, strconv.Itoa(peerDev.Volume), strings.ToLower(peerDev.PeerDiskState))
+				ch <- c.makeGaugeMetric("connections", float64(1), resource.Name, strconv.Itoa(conn.PeerNodeID),
+					conn.PeerRole, strconv.Itoa(peerDev.Volume), strings.ToLower(peerDev.PeerDiskState))
+
+				ch <- c.makeGaugeMetric("connections_sync", float64(peerDev.PercentInSync), resource.Name, strconv.Itoa(conn.PeerNodeID), strconv.Itoa(peerDev.Volume))
+
 			}
 		}
 	}
diff --git a/drbd_metrics_test.go b/drbd_metrics_test.go
index 29110d7..8f88355 100644
--- a/drbd_metrics_test.go
+++ b/drbd_metrics_test.go
@@ -117,7 +117,6 @@ func TestDrbdParsing(t *testing.T) {
 	}
 
 	// test attributes
-
 	if "1-single-0" != drbdDevs[0].Name {
 		t.Errorf("name doesn't correspond! fail got %s", drbdDevs[0].Name)
 	}
@@ -141,6 +140,11 @@ func TestDrbdParsing(t *testing.T) {
 	if 0 != drbdDevs[0].Devices[0].Volume {
 		t.Errorf("volumes should be 0")
 	}
+
+	if 100 != drbdDevs[0].Connections[0].PeerDevices[0].PercentInSync {
+		t.Errorf("PercentInSync doesn't correspond! fail got %d", drbdDevs[0].Connections[0].PeerDevices[0].PercentInSync)
+	}
+
 }
 
 func TestDrbdInfoError(t *testing.T) {
diff --git a/test/drbd.metrics b/test/drbd.metrics
index cb30a47..6b58272 100644
--- a/test/drbd.metrics
+++ b/test/drbd.metrics
@@ -2,6 +2,10 @@
 # TYPE ha_cluster_drbd_connections gauge
 ha_cluster_drbd_connections{peer_disk_state="uptodate",peer_node_id="1",peer_role="Primary",resource="1-single-0",volume="0"} 1 1234
 ha_cluster_drbd_connections{peer_disk_state="uptodate",peer_node_id="1",peer_role="Primary",resource="1-single-1",volume="0"} 1 1234
+# HELP ha_cluster_drbd_connections_sync The in sync percentage value for DRBD resource connections
+# TYPE ha_cluster_drbd_connections_sync gauge
+ha_cluster_drbd_connections_sync{peer_node_id="1",resource="1-single-0",volume="0"} 100 1234
+ha_cluster_drbd_connections_sync{peer_node_id="1",resource="1-single-1",volume="0"} 100 1234
 # HELP ha_cluster_drbd_resources The DRBD resources; 1 line per name, per volume
 # TYPE ha_cluster_drbd_resources gauge
 ha_cluster_drbd_resources{disk_state="uptodate",name="1-single-0",role="Secondary",volume="0"} 1 1234