Wide applicability: Our wrench expander is 1/2 inch or 21mm hex drivers.This key extension adapter is ideal for professionals. Tighten and loosen the washer: Designed to extend the key with another key to create more leverage. Suitable for different wrenches, loosen or tighten stubborn rusty nuts and bolts, easier to remove, save effort. To switch to tightening or loosening, you just have to put it on the other side of the key. Antirust material: Heat treated steel, to prevent rust.This universal wrench works well on rusty nuts and bolts.Resist frequent and fading. and last for years. steel construction: The sturdy construction of this master Key extension adapter prevents from slipping or finishing.Heat-treated steel construction makes the key extension strong and . Forge body key adapter. Great key extension tool: Master Key Extension adapter saves you time and effort for adding more lever heavy duty nuts and bolts,and access to hard-to-access areas., Weight: 0.55446258893 pounds, Manufacturer: Tuidzljd