This page features a super collection of St. Pat's mailbox covers. You're sure to find the perfect St. Patrick's Day mailwrap here! Designs include shamrocks, clovers, leprechaun & pot of gold. Flagsrus offers high quality, large magnetic mailbox covers from Magnet Works (Studio M). Add a splash of color with a vinyl weather resistant mailbox cover! All covers feature a slot for the postal carrier alert flag. These covers attach to the mailbox with magnets. The large size fits 8" x 21" mailboxes. No worry if you have a plastic or aluminium box, see the Adapter Kit.