1. The straight rulers are made of polystyrene plastic,  durable, not easy to break for using a long time.  2. Transparent color allows for a clear view of numbers and letters on the page. With the clear math ruler, you can measure an object easily.3. The measuring ruler does not only make you draw straight lines on one side, and wavy lines on the other, can use them to measure, and draw geometric figures, etc., providing you with large convenience, suitable for a variety of applications in classrooms, offices, and homes, for artists, designers, architects, engineers and so on.