Socket Adapter, Input Drive Size 1/4 in, Input Drive Shape Square, Input Drive Gender Female/ OVERALL LENGTH: 1.688 INCHES NOMINAL DRIVE SURFACE SIZE: 0.250 INCHES NOMINAL BOTH ENDS DRIVE END SHAPE: SQUARE FIRST END INTERNAL DRIVE END SHAPE: SQUARE SECOND END EXTERNAL SPECIAL FEATURES: LOCKING TYPE; INCLUDES HEX KEY FOR SETSCREW MATERIAL: STEEL OVERALL SURFACE TREATMENT: OXIDE OVERALL