DWYER INSTRUMENTS 1630 Large Diaphragm Pressure Switch: Visual Set Point Adjustment in 5 Standard Ranges, 0.05" to 12" w.c., Repetitive Accuracy within ±1% Highest precision conventional large diaphragm pressure switch provides maximum dependability. In addition, it incorporates a visible set point indicator for maximum convenience. UL and CSA listed, FM approved for general service, these switches are suitable for most applications in air conditioning and industrial service. Electrical capability of 15 amps handles most small electrical loads. CAUTION: FOR USE ONLY WITH AIR OR COMPATIBLE GASES Click HERE for Specifications, Diagrams in PDF