- This Reflective Mailbox Numbers Decal comes with 2 Address Stickers, One for each side of your mailbox - The Address Sticker is up to 4” high x up to 10.50” wide, depending on font and address length. - 5 CHARACTER LIMIT **Please include the numbers for the address in the Personalization Box ** This House Numbers Reflector sticker kit is cut from genuine 3M, Automotive Grade, Retro Reflective Safety Vinyl. This is the same reflective decal material used on police cars and fire trucks. They look like regular decals in the daylight, but at night they glow under flashlights and headlights. The Hyper Reflective Mail Box Transfer Set is available in 9 colors! Just choose your color from the dropdown menu.