The Mechaddy is a lever-operated retrofit that replaces the original wheels on a manual wheelchair. It attaches with the same quick-release system found on conventional wheelchairs. Users propel the chair with levers in a chest-press motion. On a forward stroke, it powers the chair forward. The reverse stroke "ratchets" back into position, much like a socket wrench. It can be switched to forward/neutral/reverse, and has a built-in braking system.