The Astro Pneumatic 1037 6pc 2-in-1 Internal/External Hex Bit Set is a multi-function Internal/External Hex Bit Set. It comes equipped with a slide sleeve to switch from the Internal, to External Function and is made with S2 steel, providing strength and durability. This item includes the following popular sizes: External Hex: 5, 6, 7, 8, 9, 10Internal Hex: 5, 6, 7, 8, 9, 10.