Beautiful little pipe plugs that keep used pipes from clogging. They have a plastic rod that fits into the tube's neck, with a sponge-yellow cap that completely seals the tip from air and debris. This will help the partially used tubing form a larger plug so it can be reused later. Now install them in a few to keep my purchase. They seem to help, you can still get a small plug that's easier to work with than without, which installs immediately after use. It also doesn't get stuck, so cleaning is better too. They work better than tape or screws. Inexpensive curing to save material.