Power Bit Holder, Input Drive Size 3/8 in, Input Drive Shape Hex, Input Drive Gender Female/ OVERALL LENGTH: 1.250 INCHES NOMINAL DRIVE NOMINAL SIZE: 0.375 INCHES SOCKET SHAPE: HEXAGON SOCKET DISTANCE ACROSS FLATS: 0.250 INCHES NOMINAL DRIVE END SHAPE: FEMALE SQUARE SPECIAL FEATURES: POWER TOOL MATERIAL: STEEL SURFACE TREATMENT: BLACK OXIDE