Extend reach when drilling with self-feed bits, auger bits and hole saws. No. 48-28-4001: Length: 5-1/2", Shank Size: 7/16" Hex, Pkg Qty: 1, Package Type: Hang Tag No. 48-28-4008: Length: 12", Shank Size: 3/8" Hex, Pkg Qty: 1, Package Type: Hang Tag No. 48-28-4006: Length: 12", Shank Size: 7/16" Hex, Pkg Qty: 1, Package Type: Hang Tag No. 48-28-4011: Length: 18", Shank Size: 7/16" Hex, Pkg Qty: 1, Package Type: Clamshell