The blank magnet templates are specialty cut to your bumper sticker. The 3" x 10" size fits DOMAGRON bumper stickers exactly. The 4" x 12" size has a little overhang. The size you choose is depending on the look that you are seeking.
Each magnet has a white and black surface so you can use these magnets for other purposes besides bumpers tickers (e.g., shelf tags, locker signs, etc.). To use for your bumper sticker, just place your bumper sticker over the white surface and apply to your bumper. No more scraping or having to worry about leaving a mark on your car from an old bumper sticker. Out with the old and new with the new couldn't be easier. Simply take the magnet off your car and add a new bumper sticker when you are tired of the old.
These magnet also comes in tow magnetic strengths. The 30 mil is the standard version. The 40 mil is the super strong version.