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.
5-degree volume control levels, built-in 24V DC forced relay and selectable power (6W, 30W, 60W, 120W): these are only some of the best-in-class features of Honeywell’s volume controller range! Design