Alvin HC12A architect's scale ruler is durable, high-quality and made of extruded aluminum. Photo-anodized calibrations are a part of the aluminum, providing a smooth, tick-free, long-wearing finish. Graduated in 3/32, 3/16, 1/8, 1/4, 1/2, 1, 3/8, 3/4, 1-1/2, 3 inches to the foot; one edge to 16ths. Hollow 12" architect scale is lightweight for easy portability. Includes hard plastic case.