This Armstrong 12" Black Oxide Finish Adjustable Wrench has a wide capacity jaw that opens up to 25% wider than standard adjustable wrenches for a use on a greater range of fasteners and a hex jaw design that allows for a more secure fit to the fastener reducing the chance of slipping. The handle is up to 70% wider for more comfort and less hand fatigue. A large serrated knurl creates a smooth, easy jaw adjustment. Manufactured from high alloy steel using the most up-to-date manufacturing process and heat treat for greater strength and durability. Meets or exceeds ASME B107.8M-1996 and US Federal GGG-W-631B specifications.