High hardness aluminum alloy holding-on:Automatic tightening,adjustable wrench, comfortable handle,Automatic tight design No stubborn:Flexible ,Turning smoothly,Turning smoothly, No stubborn, high efficiency Double-side gear design: easy tighten screws,without align repeated laser dimension:Dimension clear and beauty,Opening accurate and difficult to wear quality control:Small when halfopening,Wrench cooperate closely,No obvious deflection when using