The Telemecanique XMPA12B2144 pressure switch is used to switch single phase 220v - 240v electric pumps. This is a differential pressure switch in that it has a "High/Off" and "Low/ON" setting point which are both adjustable. This particular switch has 2 NC (normally closed) terminals and an earth screw connection plus 2 x cable gland cutouts. Click here for the technical specs. Click here for the instructions.