The Performance M871 is a 1/2-Inch Drive 21MM Deep Impact Socket. Use this socket for a variety of projects. Performance tools are made of the highest quality materials for long lasting quality. Features: * Drop forged chrome vanadium steel for strength and durability. * Rounded corners for a tighter grip. * Large size lazer etching for easy identification. What"s In the Box: * Performance M871 1/2-Inch Drive 21MM Deep Impact Socket