Check the listing for details. Flag-Up Mailbox. Color: Gray, Condition: New. Listed at 40.00 USD. The Flag-Up Mailbox is a clever and convenient solution for those who want to avoid unnecessary trips to check their mailbox. Designed to attach to your existing post, this handy device alerts you when mail has been delivered, eliminating the useless trips to check the mailbox. It's an incredibly useful accessory for rural residents, the elderly, or anyone who wants to save time and effort. Simply mount it on your mailbox post, and you'll know instantly when new mail arrives. With its sleek gray finish, the Flag-Up Mailbox mounts to standard roadside posts. Say goodbye to the frustration of checking an empty mailbox and enjoy the convenience of being alerted when your mail is ready to be collected. See full selection at flagupmailbox.com Available in standard, large, jumbo size mailboxes.