That all depends on what kind of combination tool you have:
1. M3
2. M3A1
3. M10
The M3 and M3A1 are designed for rifle maintenance and, though they can be kept in the butt stock, are usually carried separately. The difference between the M3 and M3A1 is that the latter has a chamber cleaning brush, while the former has a slotted mandrel for chamber cleaning patches. Each has a screwdriver that fits all the screw-head fasteners on the rifle and gas cylinder lock screw. There is the combination part of the tool that has a pin punch, case extractor, rear sight windage screw spanner, and bolt disassembly/assembly tool.
The M10 is part of the butt stock cleaning kit issued with the rifle. The M10 has the cleaining rod handle that doubles as a screwdriver and bolt disassembly/assembly tool. It has a hole in the end to insert a cleaning rod section for use as a T-handle wrench to remove the gas cylinder lock screw. There are four cleaning rod sections, a slotted tip for cleaning patches, and a bore brush. The rod sections, slotted tip, and bore brush are contained in a small canvas pouch that is inserted in the butt stock. There is also a small grease container that fits in the stock with the handle and cleaning patches.