The STEELMAN 60230 1/2-Inch Drive 6-Point Thin-Wall Impact Flip Socket, 21mm x 21.5mm was designed to save you time by maximizing efficiency. This dual-ended, 6-point metric impact grade flip socket allows you to work on both 21mm and 21.5mm lug nuts and fasteners without having to constantly switch sockets. Made of durable and hardened chromoly steel which is then given a black phosphate protective coating, this socket is designed to meet or exceed 150% proof of torque under ASME tool performance testing standards. Fitting easily over an impact extension or onto an impact wrench's extended anvil, this socket's recessed edges provide the most accurate fit possible, gripping fasteners by the sides and not the edges which results in reduced slippage and rounding/fastener damage. In addition, the thin-walled design allows this socket to reach fasteners where there is less side clearance. Laser-etched size callouts make identification among other sockets easy. Whether you’re a professional mechanic at a repair or tire shop, or just love to work on your own cars and vehicles, this flip impact socket set is a must for working efficiently!