The most feature rich heat alarm for residential use in its class. Features advanced rate-of-rise technology found in more expensive commercial/industrial alarms at an economical cost. Exclusive IR remote control test/silence feature provides unparalleled convenience. 135F Fixed temperature and Rate-of-Rise Thermistor heat sensor 9V Battery Backup IR Remote Control Silence/Test uses most remote controls to temporarily quiet unwanted alarms and test alarm functions Latching alarm indicator - remembers which unit initiated an alarm Two silence features - can silence the low-battery chirp for up to eight hours or temporarily silence an unwanted nuisance alarm 10-Years Limited Warranty Model # HD6135FB Weight 7.3 oz Dimension 5.4" dia x 2.2"H Operating Voltage 120V AC 60Hz w/ 9V battery backup Operating Current .05 amps (standby/alarm) Temperature Range 40�F (4�C) to 100�F (38�C) Humidity Range 10% to 90% relative humidity (RH) Audio Alarm 85dB at 10 feet Test/Silence Electronically simulates alarm condition, causing the unit to alarm. Press and hold test/silence button Alarm Reset Automatic when temperature cools below 130�F Heat Sensor Thermistor Indicator Lights/Sounds AC Power: Constant Green LED DC Power: Intermittent Green LED Local Alarm: Red LED flashes rapidly, audio alarm Remote Alarm: Red LED out. Latching Alarm: Red LED flashes after local alarm stops Listing Listed to UL539 Standard