Mersen Surge-Trap® Surge Protective Device, Type 1, Series: STT2, 347 VAC Electrical Rating, 50/60 Hz Frequency, 200 kA Short Circuit, 50 kA Peak Surge Current, 10 kA Nominal Discharge, Modes of Protection: L-N/L-L, <25 ns Response, LED Indicator, 3 ph, Environmental Conditions: -40 to 85 deg C Operating Temperature, -40 to 85 deg C Storage Temperature, NEMA 2/4X Enclosure, Panel Mounting, Pre-Wire Terminal, Polycarbonate, 4.725 in L x 3.75 in W x 2.37 in D Dimensions