Ratchet Adapter, Drive Size 1/2 in, Overall Length 2 1/2 in, Number of Pieces 1/ OVERALL LENGTH: 2.656 INCHES NOMINAL DRIVE SURFACE SIZE: 0.500 INCHES NOMINAL BOTH ENDS DRIVE END SHAPE: SQUARE FIRST END INTERNAL DRIVE END SHAPE: SQUARE SECOND END EXTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: CHROMIUM OVERALL STYLE DESIGNATOR: 147 EXTERNAL-INTERNAL SPECIFICATION/STANDARD DATA: 05047-ASME B107.10 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD NONDEFINITIVE SPEC/STD DATA: 2 TYPE AND 3 CLASS AND B STYLE