Johnson Level 420EM 16" Metal Combination Square Adjustable. Little tool, big results. Johnson's easy to use 16" combination square gives you the accuracy and precision you need for every job. Its stainless steel blade has both English and metric graduations in 1/8", 1/16" and mm that are permanently stamped, so you'll never worry about them fading or wearing. It features a durable acrylic vial and heavy duty cast zinc head with a black, chip-resistant e-coating finish. The hardened screw-in scriber stays securely in place, built to endure the toughest job site conditions. It was also designed with maximum accuracy in mind - its square head is CNC machined for greater accuracy, and the Auto-Lock blade assembly makes it easier to accurately line up your tool for use.