These are the two pieces of my skimmer riser. The skimmer is designed to work in water that is 5-8 inches deep and my sump is 12.5 inches deep. After sitting on these risers, the skimmer will only be in 6.5 inches of water. The piece in the left is a 6 inch fitting cleanout body, and the piece on the right is a 6 inch cap with a flat top. No gluing necessary.