2 Port Heavy Duty Dual Rated Transformer Lug 800 MCM - 300 MCM Heavy Duty Dual Rated Transformer Lugs are versatile and reusable set screw connectors made from high strength 6061-T6 aluminum alloy for superior electrical and mechanical performance. Two set screws per wire hole ensure an exceptional connection. Electro-tin plated for low contact resistance. For use with copper or aluminum conductors. Mounting hole spacing is NEMA 1-3/4". Meets or exceeds ANSI C119.4 Class A. Rated 600V. Temperature rating 90 degrees C.