Description: 【Comprehensive Tool】This plotter engineering ruler includes 8 scales and is matachable with all VFR aviation charts. It allows for easy conversion between nautical miles and statute miles. 【Accurate Measurements】The tool enables you to accurately measure the heading line, draw the expected flight route, solve the problem of deviating from the course, and determine round-trip bearings. 【Versatile Functionality】It features a sectional side and chart side, a nautical face and statue face. It also allows you to draw north lines and north lines, establishing flight plan checkpoint. 【Easy-to-Read Design】The opaque white background makes it easier to read scales. The top/bottom scales of regulations and nautical scales are clearly marked for convenience. 【Product Specifications】Made of durable pp material with dimensions of 20cm/7.87inch. Each package includes 1 set. Size Chart: 20cm/7.87inch Package Includes: 1 Plotter Aviation Slide Rule Note: Please allow slightly errors due to manual measurement and different monitors.