The post cube has a cylindrical opening to fit a 2 7/8¨ diameter galvanized steel pipe needed to anchor your installation. This post is also covered with a 3¨ interior diameter PVC cover and a cap. This is used not only to hide the metal pole but also to give a better plastic on plastic movement with the post cube. This particular type of anchorage is very resistant and allows your installation to follow water level variations. This is the ideal anchorage for tidal areas. Note that this system should not be used in zones where the depth is over 7' (2,25 m).