Aluminum Dual Rated Box Lugs with Turn Prevent 350 MCM-6 AWG Turn Prevent Lugs are made of 6061T-6 aluminum alloy. Electro-tin plated for low contact resistance. For use with copper or aluminum conductors. Design includes threaded mounting hole. Rated 600V (2000V max. per UL486B). UL 486A/B Listed. Temperature rating 90 degrees C.