Stencil and Ruler for ICAO 1:500'000 aviation map

This stencil/ruler features ticks every 2 nautical miles (nm) and 2 minute ticks at 80, 95, 110kts groundspeed measured from the square cornered edge marked by the arrow. At the opposite edge the tool provides a space to measure a 5+5nm corridor necessary to determine the safety altitude. Two circles help marking a waypoint, an additional stencil allows noting the leg number, heading, time, altitude and safety altitude directly on the map or a quickly removable sticker/tape (in case thats necessary inflight). 

Designed for “Staedtler Lumocolor Permanent - Fine” pencils, but should work with any pencil with a sufficiently small tip.