Vintage L.S. Starrett Co. No. C636ME 6-inch / 150mm spring-tempered steel rule. The rule has dual imperial and metric graduations with 32nds, 64ths, 0.5mm, and 1mm markings. It has a satin chrome finish stamped Athol, Mass. U.S.A. Clean condition with crisp, legible etchings and minimal shop wear.