HitchPals custom made on-board signs are made from light weight, polycarbonate palstic. The full color vinyl graphics are created using a photo imaging process and thermally transfered to the 4 inch diameter signs. The signs come with a 3/4 inch diameter suction cup so they can be attached to windows, refrigerators, filing cabinets or any smooth surface. HitchPals - a quality product made in the USA.