WW2 Japanese Navy Pilot Type 4 Flight Navigation Calculator – Knee Board – Leg Worn

Here is a World War II Japanese Navy marked flight navigation calculator. This flight calculator was strapped to the pilots thigh while in flight. It is fully functional. All the wheels and knobs turn freely.Condition is fine. The data plate is also present. Each Japanese pilot was issued one of these devices to be used prior to radar assisted navigation ability.  Pilots were instructed to fly on an azimuth for a certain distance at a certain speed. This was the device that helped them calculate those azimuths, distances, speeds so they would arrive safely at their destination on time.