The Hobie RAM Mast-Tube Wedge Mount Adapter 1.5 in. is a great way to provide a mounting point to openings from 7/8" to 1" in diameter. This mount adapter works great on the Hobie mast tube of your Hobie kayak. To attach the adapter, slide the wedge tube into the opening and tighten the screw on the top. Attach anything in your mount openings from RAM tubes or fly rod holders. This wedge mount adapter comes with a 1.5 inch RAM ball suitable for RAM rod holders.