The STEELMAN 301160 1/2-Inch Drive Impact Flip Socket, 19mm x 21mm was designed to save you time. This dual-ended, 6-point metric flip impact socket allows you to work on both 19mm and 21mm lug nuts or fasteners without having to constantly switch sockets. Its constructed of hardened chromoly steel to withstand high-torque applications. 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. Whether youre a professional mechanic or just love to work on your own cars and vehicles, this flip impact socket is a must for working efficiently!