The differential pressure switch housing unit contains a diaphragm, a snap-acting SPDT switch, and a range adjustment knob with increments. The sample connections located on the side accept 6.35mm (0.25”) OD tubing. There are various optional pressure ranges, and 2 pickup tubes and 2 m (6.56’) of PVC tubing available. The enclosure cover guards against accidental contact with the live switch terminal screws and the setpoint adjustment knob with indication.