OPEN only (all LiftMaster operators) or SAFETY only (LiftMaster operators with type B2 C2 L2 T T1 or TS control wiring) after vehicle passes over treadle.
The weight of the vehicle compresses an electric switch which sends an open signal to the door.
Requires a 2-wire connection to the operator but does not require power to function
Modification includes an explosion-proof motor explosion proof fittings operator mounted explosion-proof electrical control enclosure and n explosion-proof three button station.