Introducing the easy to use horizontal magnetic mailbox flag by PostFlag. Absolutely ZERO tools required, installs in SECONDS. Great for Houses, Apartments, PO boxes and any metal mailbox design. Safely & Securely Sticks to metal mailboxes. *We do not advise you use this product on any material but metal. For best results, wipe the surface of your mailbox clean of dirt & debris before applying your new magnetic mailbox flag. Made with the strongest outdoor-rated PVC material available. Revolutionary heavy duty multiple magnet design allows it to rest securely no matter the weather!