The slide rule is made of durable plastic material, not easy to break and melt. It can withstand high temperature. This fixed plotting ruler is ideal for aviation student training, private pilot training, search and rescue operations, and crew member training. Suitable for flight instructors use as a teaching tool to teach students how to plot routes and measure distances. The navigation plotter is calibrated according to the legal ratio of miles and nautical miles, ensuring that the scale is accurate and precise. This aviation ruler allows pilots to accurately determine their flight distance and direction. This flight plotter is fine in workmanship, using special manufacturing technology to make the printed numbers and other marks on the ruler will not fade for a long time. This aviation plotter is a double-sided printed design, easy to read the scale on each side. The sectional scale 1:500000, wac scale 1:1000000 and terminal area scale 1:250000.