Astro 1037 2-in-1 Internal/External Hex Bit Set, 6-Piece Multi-function Internal/External Hex Bit Set Slide sleeve to switch from Internal to External function Made with S2 steel providing strength and durability External Hex: 5, 6, 7, 8, 9, 10 Internal Hex: 5, 6, 7, 8, 9, 10