Check the listing for details. Vintage Map Measuring Tool Opisometer Inches To Miles and kilometers. Listed at 16.24 USD. This vintage map measuring tool is a unique piece of scientific equipment, specifically an opisometer, dating back to a bygone era. The tool is designed to convert measurements from inches to miles and kilometres, making it a valuable tool for cartographers, surveyors, and travellers alike. Its antique charm adds to its functionality, making it both a practical and decorative item for those interested in scientific instruments and historical tools.