Clamp, Two-Prong Extension, Medium, Single Adjust, 8in OAL. Nickel-plated zinc alloy clamp has high tensile strength and corrosion resistance. Fully enclosed stainless steel springs provide smooth operation. Two-prong clamps are available in single and dual adjustment. The medium clamp has a 1 1/2¿ (38mm) maximum grip size with a 1/2¿ (13mm) O.D. extension arm. The large clamp has a 2 1/2¿ (64mm) maximum grip size with a 5/8¿ (16mm) O.D. extension arm. Complete with removable vinyl and fiberglass sleeve covers.