NC, auto-drain solenoid valve for air compressor. Can preset the open and close time in the special ... easy, small shape, high reliability. Design for use withair compressor, air purifying, air station, water auto-supply and irrigation in general. Motion2/2 ... : (OFF)0.5~45minutesDrain time:(ON)0.5~10secondsCertificateISO9001/2008 air compressor solenoid valve