Impact Socket Adapter, Black Oxide, Locking Yes, Output Drive Male, Square, 1/2 in/ OVERALL LENGTH: 1.875 INCHES NOMINAL OUTSIDE DIAMETER: 1.375 INCHES MAXIMUM DRIVE SURFACE SIZE: 0.625 INCHES NOMINAL FIRST END DRIVE SURFACE SIZE: 0.500 INCHES NOMINAL SECOND END FEATURES PROVIDED: POWER TOOL DRIVE END SHAPE: SQUARE FIRST END INTERNAL DRIVE END SHAPE: SQUARE SECOND END EXTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: OXIDE OVERALL STYLE DESIGNATOR: 6 EXTERNAL-INTERNAL