Furnas 69JG & 69HA Pressure Switches are designed for use on air compressors by providing an automatic system of maintaining pressure between the two preset pressure settings. An automatic unloader valve which prevents compressors from starting under load is also available. The two pole double break contacts are silver cadmium oxide. All ferrous metal switch parts are zinc plated and dichromate treated to resist corrosion. Springs are stainless steel.