Will settle for the 16″ Tuf-Tite domed lid and the flat heavy duty lid. They have got a ring at the inside them as a way to can help you add a concrete plug for safety. (Maintain no longer Included) Tuf-Tite 16″x 3″ Safety Pan Riser will work with all other Tuf-Tite products which can be 16″ in Diameter. Comes with 6 screws to suit securely to existing Risers. Adds 3 more inches of height to existing risers.