America Forever Magnetic Mailbox Adapter Kit is a premium mailbox cover accessory that allows you to display your favorite magnetic mailbox covers on plastic/non-magnetic mailbox. Easy to install, one side has self-adhesive backing to attach to your mailbox, while the other side has a plain magnet to connect to the magnetic strips on your mailbox cover. For best use with America Forever Mailbox Covers. Measures 17 x 1 x 0.20 inch.