Ratcheting box end needs as little as 5-degrees to move fastener vs. 30-degrees for standard box end wrenches. 13 locking positions allow you to reach around obstructions to turn nuts and bolts in hard to reach places. Quickly tighten or loosen fasteners by locking the pivot joint and pumping the wrench with a push-pull motion. Lock the pivot joint in the straight position for the strength of a typical straight wrench. Up to 23% longer for excellent leverage and access to hard-to-reach fasteners. Stronger grip on fasteners and up to 25% more torque.16mm 12-5/16"