Socket Bit, Insert Length 4 1/8 in, Replaceable Insert No, SAE, Tip Size 5/16 in, Tip Style Hex/ OVERALL LENGTH: 5.625 INCHES NOMINAL BLADE LENGTH: 4.125 INCHES NOMINAL WRENCHING SURFACE SIZE: 0.312 INCHES NOMINAL SINGLE END DRIVE SURFACE SIZE: 0.500 INCHES NOMINAL SINGLE END FEATURES PROVIDED: MANUAL TOOL AND WRENCHING SURFACE SHAPE: HEXAGON SINGLE END EXTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: CHROMIUM DRIVE SURFACE SURFACE TREATMENT: OXIDE STYLE DESIGNATOR: 187C HEXAGON