The OEM Staedtler Architectural Triangular Scale STD9871931BK is a 12" triangular scale designed for students of architecture. It features three sides with six different scales, including die-engraved graduations that are easy to read and will not rub off. The architect triangular scale includes measurements fully divided in inches to 16ths, with scales for 3/32", 1/8", 3/16", 1/4", 1/2", 3/4", 1", 1-1/2", and 3" = 1'. Made of high-impact polystyrene plastic, this scale is durable and reliable for all your architectural needs.