The SUNEX Tools 3/4 in. Drive 21mm 8-Point Impact Socket, Model 421MSS, is engineered for professional and industrial applications requiring reliable performance with square-head fasteners and pipe plugs. Constructed from high-strength chrome molybdenum alloy steel, this impact socket is designed to withstand the demands of high-torque impact use. Its eight-point square geometry provides a precision fit that reduces slippage and ensures secure fastener engagement. The socket features a durable black phosphate finish that offers excellent corrosion resistance for extended service life. Laser-etched dual size markings enhance visibility for quick identification, even in low-light environments. This impact-rated socket is specifically designed for use with impact wrenches and pneumatic tools, meeting or exceeding ANSI and ASME standards for impact sockets to ensure safe and reliable operation. Backed by the SUNEX Tools lifetime **with no exclusions, this socket combines durability and performance for demanding work environments.