Evergreen Monogram "E",Magnetic Mailbox Cover,18x24 Inches 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.