3M™ Scotchlok™ Copper Two Hole Lug 31129 has a 1/2 in (1.3 mm) stud size, a 0.42 in (10.6 mm) O.D., and a 4.85 in (123.2 mm) length. One piece seamless design. 3M™ Scotchlok™ Copper Two Hole Lug 31129 has a 1/2 in (1.3 mm) stud size, a 0.42 in (10.6 mm) O.D., and a 4.85 in (123.2 mm) length. One piece seamless design.