Outdoor & Car Magnets 30 Mil Round Corners will be one of the best promotional items you have every utilized. The advantage with these custom rectangle magnets is that they are small and so they can be placed neatly to a metal surface that will never go off. Apart from sticking flyers on cars just leave these magnets somewhere on the side and see the enquiries that are coming. Order these waterproof, UV safe and fade resistant magnets now.