The 34 in. – 4 in. x 4 in. OZ-Post Anchor T4-850 (3 1/2″ x3 1/2″) is the only post anchors industry tested to be the very best. 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. These posts are made with hot-dipped, galvanized steel and wind load tested to 120 mph for privacy fencing for maximum strength. The genius of these drivable instant post anchors is in the patented design that provides similar stability to 6-8 in post hole in concrete while keeping the bottom of your posts safe from water, rot and yard maintenance tools. Easily installs with a manual driver or a Jackhammer.