Dry erase polar grid boards from OptiMA®. We offer a traditional 4' x 4' size but we also offer two things that our competition doesn't! First, we have both a magnetic and a less expensive non-magnetic polar coordinate dry erase board. If you're not interested in using magnets or magnetic accessories why be forced into buying a more expensive magnet board? We give you the option of selecting either a magnetic or a non-magnetic format. Secondly we offer a smaller 32"" x 45.5"" size board that doesn't have to ship by truck but rather can ship UPS oversized for a fraction of the cost. Nice! All of our coordinate grid boards are made with our exclusive OptiPrint® method which makes the images crisp, clean and permanent. They're completely protected under our exclusive clear dry erase writing surface that with proper care will last for years and erase completely without ghosting.