Of all the multi-tools we’ve seen, this is by far the smallest and easiest to carry. The KeyTool Multi-tool goes on your keyring. But even better than that, it wraps itself around one of your existing keys, adding next to zero bulk or weight. And for such a tiny piece of equipment, there’s a lot of utility on board. It has three different sized screwdrivers, a nail file, finger nail cleaner (?), bottle opener, wire cutter, and tweezers. Made of 422 grade stainless steel.