Proto Spline Reversing Combination Ratcheting Wrenches 15 angled offset box end helps keep shank clear of obstructions. Anti-Slip Design (ASD) open end. The chrome-vanadium switch lever allows for easy changes in turning direction which helps improve speed. Loads are kept off the corners of the fastener which helps prevent fastener rounding. Patented locking grooves help prevent the wrench from slipping off the fastener when turning Pack of 1