Attach this optional one piece welded extension frame to the RS-56X168- UG Universal Grid to provide a safe suspension platform for medium to large clusters of subs. It comes equipped with a structural splice kit that permanently joins the extension frame to the main grid. Only simple hand tools are required. Once attached, the assembled Grid and Extension frames are suspended under the venue’s super structure from strategically placed rigging points. The sub cluster is then rigged under the extension from its own Top Grid leaving plenty of room for the main line array cluster to be raked back toward the subs into its optimum position. This extension frame is constructed of tough tubular steel alloy and treated to a rich lasting black powder coat finish.