Large dry erase polar coordinate magnet. What a great way to have a dry erase polar coordinate graph in your classroom. When needed you simply take it out of the corrugated shipping tube it comes in and roll it out onto your magnetic classroom whiteboard. When you're done with that lesson plan or section of your curriculum you roll it back up with the print facing out and store it until you need it again. The polar coordinate grid is printed onto a heavy duty white vinyl. Then we laminate the print with our exclusive clear dry erase writing surface protecting the print. Finally the whole thing is laminated again onto a heavy gauge magnetic sheet that sticks securely to any smooth steel surface like a magnetic classroom whiteboard or chalkboard. Our dry erase polar coordinate magnets are manufactured in the U.S.A. and school purchase orders are accepted.