Staedtler(R) Engineers Printed Scale 12-Inch triangular scales are ideal for engineers and engineering students Three sides with six different scales feature die-engraved graduations Easy-to-read, printed graduations will not rub off Color-coded grooves allow quick and accurate selection of the desired scale Engineer triangular scales are fully divided: 10, 20, 30, 40, 50, 60 parts to the inch. Scales are made of high-impact polystyrene plastic