Alumicolor s solid aluminum drafting scales are the ultimate for accurate professional use. Satin-smooth anodized aluminum scales are a pleasure to use. Alumicolor s scales are truly professional with the full six scales on each one and ultra smooth mark resistant surface.The Engineer scales have the following calibrations: 10 20 30 40 50 60 parts to the inch.Each scale measures 12 in. in length. • Satin-smooth anodized aluminum scales are a pleasure to use. • Alumicolor s scales are truly professional with the full six scales on each one and ultra smooth mark resistant surface. • The Engineer scales have the following calibrations: 10 20 30 40 50 60 parts to the inch. • Each scale measures 12 in. in length. • color: gold. • Sold as 1 Each.