This Anti Entrapment Suction Outlet Cover acts as a safety measure, preventing entrapment. It is for single or multiple drain use. The retrofit adapter frame easily and safely retrofits most brands existing 9" mud frame with epoxy or screws or both machine screws. It is ideal for retrofitting over all existing sumps and frames up to 13" by anchoring it directly into the pool finish using four brass anchors and stainless screws in kit #BIK4.