The Danray Products Sander Safety Scale is designed to verify that the openings between the belt and disc and the tables on sanders are 1/8" or less. The scale is made out of durable, 0.090" thick anodized aluminum and offers easy-to-read text and graphics that will not rub or scratch off. The scale is convenient to carry and store. There is a 0.25" hole in it for attachment to sanders and a ruler along the back edge to measure openings for compliance.