TEKTON 4971 3-Pc. 1/2" Drive Impact Extension Bar Set features: Drop Forged, Heat Treated Chrome Vanadium Steel, Oil-Quenched, Black-Oxide Finish for Durability, Hole on Bar for Locking onto Drive Tang, Specially Designed for Use with Air Tools, 1-pc. 1/2"-Dr x 3" Extension Bar, 1-pc. 1/2"-Dr x 6" Extension Bar, 1-pc. 1/2"-Dr x 8" Extension Bar.