The 27 in. OZ-Post Mailbox Anchor MB-24 (3 1/2? x3 1/2?) is designed specifically for the installation of a mailbox or other small projects. OZCO’s OZ-Post post anchors are a better option to post hole diggers and pouring concrete footings, providing superior support for your outdoor living spaces and future project. OZ-Post products anchor your wood post with no digging, concrete or mess while keeping the bottom of posts safe from water and rot. Easily installs with a manual driver or a Jackhammer. The 27 in. OZ-Post Mailbox Anchor MB-24 has a black powder coated steel with “built-in” attractive post base and is suitable for contact with ACQ treated lumber, which can be secured with wood screws and/or adhesive (not included). Use our OWT hardware to dress up your mailbox post, pergolas, and outdoor living structures for an OWT standing finish.