The IQ651H is an intelligent Heat Detector with both fixed-temperature alarm and rate-of-rise alarm characters (Temperature 135º F/57º C) is a UL listed device according to UL 521 for Fire Protective Signaling Systems for indoor use and FM. It features a slim design that combines visual appeal with a high standard of reliability. The detector has a Microcontroller Unit (MCU) performing comprehensive self-diagnostic tests, and result analysis. The IQ651H is intelligent, addressable, and takes one address on the signaling Line Circuit (SLC) of the fire alarm control panel.