4 Ga. 5/16" Stud Heavy Duty Corrosion-Resistant Copper Lugs - (Pack of 10) Ships same business day. Offers 80% greater wall thickness than a standard lug for extra durability. Tin plated for superior corrosion resistance. Seamless copper lugs offer superior corrosion resistance over "sandwiched-end" lugs. UL Listed, CSA Certified