A main fixed housing sleeve provides a location for the push-button assembly. This has a top section that engages a sleeve under spring bias. The contact of the bulb engages a sleeve and this locates in a carrier. When the push-button is actuated the carrier moves downwards against a spring and engages fixed contacts that connect with conductors. A centre pin has a dowel that moves in a latching track to retain the unit in the actuated state.
