Design Features Set points stay set not sensitive to shock, vibration, temperature variations, or other ambient conditions No "tracing" of fluctuating pressures no "teasing" of the electrical element. The switch is either "on" or "off." Reduces the adverse effects of pump ripple, contact chatter, fatigue, premature wear, and other common switch problems Maximum life expectancy with lifelong reliability and precise repeatability assured A wide range of set points available in each switch model series. 646 Series Features Explosion Proof Div. 1, 2 U.L./CSA Fire Resistant Steel Body Specifications Port Connection Type NPT Female Port Size 1/2" Connection Material Stainless Steel Circuitry SPDT Diaphragm/Pistom Material Polyimide Switch Setting Field Adjustable Electrical Connection Male conduit, wire leads Special Options Explosion Proof Min 4 VAC Set Point 26