Remote Alarm Accessory, Finish Steel, Wall Mounting, Alarm Current 30mA @ 24V DC, Depth (In.) 1 1/2 in, Height (In.) 4 1/2 in, Length (In.) 2 3/4 in, Width (In.) 1 1/2 in, Voltage 24V DC, Standards CSFM, cUL, MEA, UL, Includes Remote Key Test Station with Pilot and Alarm LED, For Use With All APC Duct Smoke Detectors