This Sign Support Base will hold a 2 3/8" inch round traffic sign post. The base may be bolted onto concrete or asphalt roadway surfaces and will allow you to install a round traffic sign post without breaking a hole in the roadway. These bases use compression bolt to secure the post to the base. The base is constructed of steel with a galvanized finish. The sign post support base has 4 holes for adding your anchors. Mounting Screw Anchors Sold Separately.