size: 1/4'', 3/8'' , 1/2'' This 3 Piece Hex Shank Bit Driver Extension Bar Set Is Designed To Meet A Variety Of Needs. Fits Snugly And Securely In Your Drill Chuck Or Hand Held Driver. Consisting Of Your Most Common Bit Sizes 1/4″, 3/8″, And 1/3″ Changing Shank Sizes. Provides Versatility And Convenience No Matter Which Tool You Chose To Use. Great For The DIY,automotive Repairs,household Maintenance, And Most General Repairs. A Great Tool Addition To Any Tool Box Set.
material: 45# carbon steel with chrome plating