The i4Interface Module connects up to 12 detectors to a wide range of control panels using only 2 to 3 zones. Compatible with the i4Series carbon monoxide (CO) and smoke detectorCOSMO-4Wand i3Series smoke detector4WTA-B. Also known as -System Sensor By Honeywell-Us 4W INTERFACE MOD REQ F/ COSMO4W - BK-COSMOD4W