The 20P-30 Pressure Swichgage instrument has a 2 inch (51 mm) dial, and a pressure range of 0-30 psi. The gage mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break resistant lens and a polished, stainless steel bezel help protect this rugged instrument. Accuracy and protection from moderate overpressure is assured by a unique, unitized diaphragm chamber. A built-in pulsation dampener helps eliminate pointer flutter and is removable for cleaning. The gage pointer acts as a pressure indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contacts are grounded through the case and have a self-cleaning motion to ensure electrical continuity.