The unit at the top was made from soft plastic tubing, about 1/2 inch ID X 2 inches long, Cut the tube and make sure then ends are clean and square. Get a plastic plug or cork and coat it with hot melt glue, then push it in the end to seal it off. To use, Pinch the soft tube flat so all the air is removed, hold it closed and place over nipple, and let go. Your whole nipple will be pulled into the tube with great suction for bigger nip growth.
The unit at the bottom, is a plastic syringe you can by at craft store. Its about 3/8 inch ID, Cut the plastic needle end off, and smooth the edges and make sure it is square. The green clip is used to hold the plunger out once, you sucked your whole nipple out to prevent the plunger from moving back.
Technique: I made two of each, both work well. Ive been attaching the nip tubes on both nipples as my asshole is getting devestated, making me more horny for anal. However, when the anal get ruff and heavy, these usually come loose, then I have big huge exposed nipples and a giant loose asshole for abuse.