U.S. Mail Delivery Magnetic Sign. Rural Delivery Carrier Magnet USPS - 6"X12" EASY TO APPLY  USPS carrier magnet for rural mail delivery. Easy to apply to vehicles, just stick it to the desired metal area on the car. WATERPROOF  This high quality magnetic sign is made with waterproof materials to allow for use in all types of weather conditions. HIGHLY VISIBLE  Sign can be seen from far away. Lettering on sign is colorful, bright and contrasts well from the white background. DIMENSIONS  Rounded corners, 6x12 inches, 0.35 mil thick! Strong, full-sheet vinyl.