90/110 PSI 12V 3.5A Heavy Duty Air Pressure Control Switch Train Horn Compressor Rated 110/90 PSI This pressure switch is designed for high-pressure on-board air systems. Ideal for air horns that require high air pressure. Preset to turn on the compressor when tank pressure is below 120 psi, and turn off the compressor when the air tank pressure reached 150 psi,with a tolerance of10%. With 1/8inch male pipe thread,and 1/4inch push-on electric terminals.