Box End Wrench, Alloy Steel, Chrome, Head Size 19 mm, 21 mm, Overall Length 9 1/4 in, 0°/ OVERALL LENGTH: 234.7 MILLIMETERS NOMINAL WRENCHING SURFACE SIZE: 19.0 MILLIMETERS NOMINAL FIRST END WRENCHING SURFACE SIZE: 21.0 MILLIMETERS NOMINAL SECOND END WRENCHING SURFACE SHAPE: 12 POINT BOTH ENDS INTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: CHROMIUM OVERALL STYLE DESIGNATOR: 144 STRAIGHT DOUBLE HEAD SUPPLEMENTARY FEATURES: INDUSTRIAL QUALITY (IQ) TOOLS PROGRAM ITEM