Little tool, big results. Johnson's easy to use 12" Structo-Cast combination square gives you the accuracy and precision you need for every job. Its stainless steel blade has English graduations in 1/8", 1/16" and 1/32" that are permanently stamped, so you'll never worry about them wearing or fading. It also features a durable acrylic vial and heavy-duty Structo-Cast molded reversible head with a lock bolt and steel screw to ensure your measurements are spot-on every time. It was also designed with maximum accuracy in mind - its Auto-Lock blade assembly ensures precision alignment for optimal tool performance.