Efsr-gfi Series 1-gang Ground Fault Circuit Interrupter, Voltage Rating: 125 Vac, Amperage Rating: 20 Amp, Frequency Rating: 50 - 60 Hz, Trip Type: 5 Milamp Trip Setting, Enclosure: Nema 3, 3r, 7bcd, 9efg, Material: Malleable Iron, Mounting: Surface Mount With 1 In Feed-thru Hub, Standard: Class I, Group B, Class I, Groups C, D, Class Ii, Groups E, F, G, Class Iii, Ul Listed: E81751, Ul Standard:943, 1203, For U-line 20 Amp Receptacles