CYA Square Aviation Protractor

Lexan resin plastic will never warp, melt or break in high temperature environment!
5-1/8” square size protractor with 0-360 scale on outside edge, a perfect easy-to-use tool for flying school students.
Showing NW, NE, SE, SW on each corner, 1:500,000 nautical miles scale includes 5 NM and 10 NM radius rings.