Most "miracle tools" make you buy into a whole new system. This doesn't. It comes with 3 adapters + a 1/4" hex socket, covering ¼", ⅜" and ½" drive, so whatever sockets you've already got in your set just click straight on. You put your own ratchet or impact wrench on one end, your own socket on the other, and go to work. No special sizes to hunt down, no kit to replace. It slots right into the gear you already trust.