The scupper venturi consists of two parts: one top and one bottom. They are fixed together with a screw from the top. By tightening the screw, the two parts are wedged into the scupper hole. The advantage of this system is that no holes are drilled into the hull of the boat to install the venturis. If one breaks, it won’t damage your kayak in any way, and it is super easy to replace, if needed.