EXTRA LARGE SIZE MAGNETIC ROOF SIGN, This is in-your-face advertising at it’s best, the Hi-Profile XL roof sign means business…literally. One metre wide and up to 30″ high, it comes with 4 high power magnets and a strap that inserts through the windows if required, ideal for placing on a main road if your business is located off it. Get the message across with one or more of these.