JOHNSON Sensitive Differential Pressure Switch, SPDT, 0.05″ Wc to 5″ Wc, Adjustable with Scale Plate, U Bracket, Nema 1, 1/2 Horsepower, 120/240 Vac, Supplied with 1/4″ Compression Fitting, 4″ Extension Tube, Mounting Screws, “O” Gasket and Angle Barb Fitting Installed