FMM-1 is a standard-sized module (typically mounts to a 4" [10.16 cm] square box) that supervises either a Class A (Style D) or Class B (Style B) circuit of dry-contact input devices.
The Pyrotector Model 30-3003 Explosion Proof Smoke Detector is a sensitive yet rugged protection device that is designed for use in hazardous industrial and commercial locations.