Heat Detector, 135 Deg F, Finish White, Ceiling Mounting, Depth 2 In, Height 5 In, Length 5 In, Coverage 2500 Square-Ft, Amps AC 1.0 Amps @ 6-28 VDC Fire Alarm Initiating DevicesWhen activated, devices send signals on a hardwired connection to initiate an alarm.Heat DetectorsRate of rise: Temperature increase at the sensor of 15 F (9 C) or more per minute activates the rate-of-rise feature; self-restoring. Fixed temperature: If temperature of the center disk rises to the sensor's rated temperature, the fixed temperature element activates. Nonrestorable and nonreusable. Once activated, the detector must be replaced.All heat detectors are UL Listed and FM and CSFM Approved, except 16X271 to 16X274 are UL Listed and FM Approved and 16X275 and 16X276 are UL Listed.Contact rating: 3A at 125VAC, 1A at 28VDC, 0.3A at 125VDC, 0.1A at 250VDC 2500 sq. ft. coverage