Copper Solderless Lug, 3/0-4 AWG with 3/8" Mounting Hole is made of 99.98 pure electrolytic copper. Steel-plated screws to prevent rusting. 25 to 70 ampere size and has 3/8" hex head screws. Rated 600 volts max. UL 486 Listed. Temperature rating 90 degrees C.