Abstract: A contactor assembly has a pneumatic actuator coupled in driving relationship with a contact arm for affecting opening and closing of at least one pair of contact tips and has a magnet valve coupled between a source of actuating air pressure and the pneumatic actuator. The valve includes an air inlet port, an air outlet port and an air exhaust port. Resilient valve seats are incorporated in the valve for sealingly engaging metallic seats on a separable valve stem. In one form, an integral filter assembly is incorporated in the valve to filter inlet air. In another form, an in-line filter is coupled to the inlet port for filtering air.