Ideal for carpenters and other professional craftsmen. Constructed of boxwood, 25% thicker than competitive wood rules, with black markings embedded in a white background protected by a clear abrasive-resistant coating. Strong lock joints eliminate end play and retain accuracy. End caps and strike plates are brass-plated. Double graduations on both edges and both sides. Graduated in feet to 1/10 and 1/100 of a foot with regular outside markings in feet and inches to 1/16".