Stanley 64R Engineers, precision, rigid steel, rustless rule, metric/imperial on 2 sides, 4 edges. Imperial side is graduated to 16ths, 32nds, 64ths, 10ths, 20ths, 50ths, 100ths. Metric side is graduated to 0.5 mm. Class 1 rule. Length. 150mm (6 in) Width 19 mm Thickness 0.45 mm