Impact Socket, Socket Size 21 mm, Socket Shape 6-Point, Drive Type Impact, Drive Size 1/2 in/ OVERALL LENGTH: 41.2 MILLIMETERS NOMINAL WRENCHING SURFACE SIZE: 21.0 MILLIMETERS NOMINAL SINGLE END DRIVE SURFACE SIZE: 0.500 INCHES NOMINAL SINGLE END FEATURES PROVIDED: POWER TOOL WRENCHING SURFACE SHAPE: 6 POINT SINGLE END INTERNAL DRIVE END SHAPE: SQUARE SINGLE END INTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: OXIDE OVERALL STYLE DESIGNATOR: 168 INTERNAL-INTERNAL SPECIFICATION/STANDARD DATA: 05047-ASME B107.33 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD NONDEFINITIVE SPEC/STD DATA: 1 TYPE