2 pole connection. Has long shaft for exposed control knob. Replaces No. WH7-D. Can be used to replace thermostats on most residential electric water heaters. Thermostats are set at 120 F. and are adjustable between 110 F. and 160 F. Thermostats include a Safety Energy Cut Off (ECO), that cuts off all power to the heater should internal tank temperature reach 190 F. (The 9000507, Lower Thermostat, does not require an ECO) Thermostat and ECO are UL listed. Fits water heaters with Apcom, Robertshaw, and Therm-O-Disc thermostats. Original part for: A.O. Smith, A.O. Smith Canada, American, GSW, John Wood, Kenmore, Lochinvar, Maytag, Mor-Flo, Penfield, Reliance, Sears, State Industries, U.S. Craftmaster, Whirlpool. Fits: Bradford White, General Electric, Rheem, Richmond, Ruud