BRK First Alert Hardwired Heat Alarm

BRK First Alert Hardwired Heat Alarm with 9V battery backup. 120V AC/DC 135F with Rate-of-Rise Heat Alarm. Understanding Rate of Rise: This allows the unit to sense a heat rise and alarm prior to reaching the fixed temperature. The alarm will sound when the microprocessor senses a temperature rise of a set number of degrees per minute. This enables a more rapid response to a potential fire. Thermistor heat sensor. Latching alarm indicator remembers which unit initiated an alarm. Two silence features: silence the low-battery chirp for up to eight hours or temporarily silence an unwanted nuisance alarm.