safe silicone, suitable for freshwater and saltwater, not easy to fade The use of buoyancy allows the jellyfish to dive without sinking to the bottom Contains the fishing line The jellyfish ' s dive position can be adjusted according to the length of the fishing line It will make the fishank beautiful and also add fun to your life Suitable for most aquarium landscapes The proper of water also helps the health of the fish It can help you observe the direction of water in the fishtank No for edges