The 7/16" Universal Quik-Lok extension has an innovative design that fits all 7/16" shanks, with or without a power-groove. The unique design requires no tools to change out bits, making it fast and efficient. These high speed steel extensions are impact rated. No. 48-28-1030: Length: 5-1/2", Shank Size: 7/16", Pkg Qty: 1, Package Type: Card No. 48-28-1040: Length: 12", Shank Size: 7/16", Pkg Qty: 1, Package Type: Card No. 48-28-1050: Length: 18", Shank Size: 7/16", Pkg Qty: 1, Package Type: Card No. 48-28-1060: Length: 24", Shank Size: 7/16", Pkg Qty: 1, Package Type: Card