Clings to your mailbox in a snap and fits all standard sized mailboxes * All-weather and fade resistant * Coated PVC design is backed with full surfact magnet * Includes a set of self-adhesive, reflective numbers * Fits all standard size mailboxes,the size is: 18"x24"; For plastic mailbox, please pick our "Evergreen Magnetic Mailbox Cover Adapter Kit,17x1.5 Inches" or check "ASIN: B006XF571I" in order to use it.