Square Clip Tube Ends S&W P/N Thread Tube O.D. Tube Screw Thread SW-130101 1/4-20 1″ 16/18 GA Zinc Plated SW-130110 5/16-18 1″ 16/18 GA Zinc Plated SW-130113 5/16-18 1-1/4″ 16/18 GA Zinc Plated SW-130141 3/8-16 1″ 16/18 GA Zinc Plated