Bold red and black markings contrast against white or natural pine finishes. Clear, abrasive resistant coating, riveted lock joints, brass plated end clasps and strike plates prevent wear. Graduated slide rule extends up to 6 inches. Slide rule runs under friction in T-slot and stops at each end to prevent slide from falling out. Marked both sides and both edges. Graduated to 1/16ths of an inch, 16 inch stud centers in red, regular outside markings. Rules with hook the zero falls at inside of hook, for distance measuring. Rules with flat, inside markings; numbering begins on inside of rule.