Field-adjustable, universal switches that can sense positive, negative, or differential air pressure;The switches use a diaphragm and an integral, snap-acting SPDT switch with three 90 Degree quick-connect spade terminals;The set point is adjusted with an Allen wrench and an indicator window;Two standard set-point ranges are available, covering 0.15”–10.0” W.C. applications;Kit includes a bracket, orifices, and 2 feet of 3/16” ID silicon-cured tubing