Staedtler - Triangular Scale Plastic Architects Ruler, 12", White Versatile three sides with six different scales. White plastic; 12" length. Architects: Open divided 3/32, 1/8, 3/16, 1/4, 3/8, 1/2, 3/4, 1, 1-1/2, and 3 = 1 foot; Full divided inches to 16ths. Engineers: Full divided 10, 20, 30, 40, 50 and 60 parts to the inch.