Square D™, EMD23F, Surge Protective Device, Series: EMD, 208Y/120 V AC Electrical Rating, 4 Wires, 300 kA Peak Surge Current, 20 kA Nominal Discharge, Modes of Protection: L-N/L-L/N-G/L-G, 3 ph, Environmental Conditions: -4 to 149 deg F Operating Temperature, NEMA 4 Enclosure, Lug Terminal, Steel, 12.008 in H x 17.50 in W x 6.5 in D Dimensions,