4/0 gauge 5/16" stud heavy duty corrosion-resistant copper lugs. Offers 80% greater wall thicknesses than a standard lug for extra durability. UL Listed and CSA certified. Thicker walls and a tin plating for corrosion resistance make these the toughest lugs available. Made of 99.9% pure conductive ETP copper. Copper lugs are clearly marked for wire size. Features a flared and chamfered barrel to ease application of finely stranded wire or welding cable.