Chemetron Chemetron Fire Systems 502 Heat Detector Head Rrd2 3.0A 6-125V.A.C., 1.0A 6-28 V.D.C. MSRP: $108.99 Chemetron Fire Systems 502 Heat Detector Head Rrd2 3.0A 6-125V.A.C., 1.0A 6-28 V.D.C.Chemetron Fire Systems, Inc.Spot Fire LowecatorMod.No. 502 Rate Of Rise & 190°F.T.759G Heat... Add to Cart Add to Cart Add to Wish List Add to My Wish List Create New Wish List