IRWIN 88601 Bit Extension, 1/4 in Shank, Hex Shank, Steel

For all wood bits with 1/4 in round shanks, three flats on shank. Follows 5/8 in and larger bits through hole. Heavy-duty, double set screw type, adds 6 to 12 in to regular bit lengths. Forged of finest quality tool steel. Allen wrench included.