Box End Wrench, Alloy Steel, Chrome, Head Size 3/8 in, 7/16 in, Overall Length 5 1/2 in, 0°/ OVERALL LENGTH: 5.500 INCHES NOMINAL WRENCHING SURFACE SIZE: 0.375 INCHES NOMINAL FIRST END WRENCHING SURFACE SIZE: 0.438 INCHES NOMINAL SECOND END WRENCHING SURFACE SHAPE: 6 POINT BOTH ENDS INTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: CHROMIUM OVERALL STYLE DESIGNATOR: 144 STRAIGHT DOUBLE HEAD