The Heat Detector FW521 is  Addressable, Intelligent and UL and ULC Listed device according to UL-521 and ULC-S530 for Fire Protecting signaling systems for indoor use with both fixed temparature alarm and rate of rise alarm characterstics. 

Capabilities: The FW521 is Intelligent Addressable and takes one address on the signaling line circuit of the fire alarm control panel. 

Compliance: UL, ULC, FM, FCC Listed. 

Design: The Heat Detector is a slim Design that combines visual appeal with a high standard of reliability.