U.S. Mail Delivery Magnetic Sign Rural Carrier Magnet USPS 5 Piece Set Red 5 Piece Magnet Set Get your custom look while alerting other drivers who you are. commercial grade magnet material .03" thick. This Set consists of 2 door signs that are 8" x 17.5", 2 signs for the rear that are 3" x 14.5". Plus a door guard blank magnet that is approx. 5" x 18".