This mason's spacing rule is designed for standard brick. The popular red end brick rule means quality. The rule extends its 12 legs out to a complete 72". Ten courses of spacing are marked on one side of the rule. The other side is marked in inches, eighths, and sixteenths. Markings at 16" for stud markings. Made from thick hardwood for long wear. Each leg is squared to fit perfectly in corners. Remember to keep your rule working well keep the joints oiled.