PurposeUsed to adapt "keller" ratchet drive wrench to multiple nut sizes of the ratchet drive wrenchUsed WithKeller ratchet drive wrenchWrench Size7/16Opening Shape12Wrench End TypeSocketWrench Body TypeStraightWrench VariationStandardDrive TypeExternal HexDrive Size7/16Head Outer Diameter0.63Overall Length0.87