Vintage Opisometer - Map Metric Converter

Vintage Opisometer Map Distance / Nautical Miles Measuring Wheel.

This tool is used for following a route on a map with the small front mounted wheel and it will read the distance on the wheel.

Great for off road treks, uncharted routes and coastlines etc...

3.5cm diameter - 10.5cm long

Condition: Some clouding to the glass but still in working order.