Gibraltar Mailboxes Rust-Proof Plastic Red Mailbox Replacement Flag Kit RFL10000 When it’s time to replace a worn damaged or missing plastic mailbox flag the mailbox flag kit provides a convenient solution. The red flag is easy to install and made from durable and sturdy polypropylene plastic so it will not rust. Mounting hardware i Flag accessory can be used to replace worn or damaged mailbox flags Made from plastic materials guaranteed not to rust Stylish red color complements any mailbox and stands out to alert carriers Easy to assemble and install Fits most USPS approved mailboxes 12 x 6 x 2 inches