Double-ended wrench for moving around obstructions. Fits 1/2" and 9/16" lock nuts. Use an adapter to join wrenches or attach the wrench to a 3/8" ratchet or extension . This double-ended wrench has the ability to reach around obstructions to turn the distributor lock nut. It fits 1/2" and 9/16" lock nuts. Also, use an adapter to join wrenches or attach the wrench to a 3/8" ratchet or extension. This clamp wrench is very handy and easy to use.