... with cheap price 4)material:PS Feature: 1) magnetic roof top car sign 2)color:red,green,yellow,bule,grey3)size ... bottom has strong magnets, can be fixed in the car top, and anti-scrape flower design to keep, maintenance vehicles ... surface. Triangular design allows visability from all sides. Hats nest for easy stacking. size:15.5(diameter) ... Off, or with a blank dry erase area. magnetic roof top car sign