Rheem SP10552MH Resistored HWD with Screw-In 240-volt/4500-watt Element Element - 240V/4500W Copper resistored hwd - 1 in screw-in Watt density classification: hwd, input Voltage (V): 208, input Voltage (V): 240, wattage at 208V (w): 3380, watt density at 208V (w/sq. In.): 156 Element diameter (in.): .260, element length - flange to tip (in.): 13.50, mounting Type: threaded, ACTUAL thread size - outside diameter.): 1-9/32 High watt density