Features: Chrome Vanadium Steel Construction with (2NI-1Cr) Black Phosphate Coating Greater jaw capacity supports larger nuts and bolts. Measurement scales (in. on front mm on reverse) are handy for sizing nuts, pipe and tube diameters. Longer jaws grip better avoiding slippage or nut round off. 4 thread knurl & Non-protruding jaws provide greater capacity; minimal head width improves performance in confined spaces.