Bionic Grip™ Wrenches - These innovative wrenches automatically adjust to the correct fastener size. Just place the wrench head over the nut or bolt and squeeze the handles to close the jaws for a snug fit. No more searching for that odd-sized socket. Each wrench has four toothed jaws that firmly grip hex heads by the flats. Because the jaws are toothed for grip, they can even turn damaged nuts and pipe or tubing.