A device for rotational connection between structural members. A generally cylindrical housing may have a central cavity therein with an open bearing end and an open plug end. A shaft at a first end may be inserted into a bearing and retained therein. The bearing may be disposed in the open bearing end and retained by a first fastener ring. A second end of the shaft may protrude outwardly from the housing through the open bearing end. A plug may be threadably engaged with the open plug end that is threaded. The plug may be positioned at an interior end to be adjacent the first end of the shaft that may have a convex surface.