4x4 Mailbox Post Protector Guard (Mill Finish) - Wood Post Trimmer Shield Designed to fit on posts with actual dimensions of 3 1/2" x 3 1/2" or slightly smaller. The mailbox post guard will protect the 4x4 post from the weed eater and it looks great too. Made from 5052-H32 .090 Aluminum so it won't rust. Comes as a two piece set with SPAX installation screws. Can be installed on posts to prevent further damage.