Lang - Magnetic, All-Weather, Standard-Size - Mailbox Cover - Blessed and Thankful, Exclusive Artwork by Tim Coffey Exclusive Artwork by Tim Coffey Magnetic, all-weather vinyl, attaches securely to metal mailboxes. Includes magnetic adapter strip for wood and plastic mailboxes. Fits standard-size, rounded mailboxes, approx. 9"h. Mailbox cover dimensions: 17.75" x 20.75"