--- includes/discovery/sensors/timetra-port-mib.inc.php
+++ includes/discovery/sensors/timetra-port-mib.inc.php
@@ -542,7 +542,7 @@ foreach ($oids as $chassis => $transeiver) {

     // Rx Power
     $descr     = $name . ' Rx Power';
-    $class     = 'power';
+    $class     = 'dbm';
     $oid_name  = 'tmnxDDMRxOpticalPower';
     $oid_num   = '.1.3.6.1.4.1.6527.3.1.2.2.4.31.1.21.'.$index;
     $value     = $entry[$oid_name];