Since its launch, it has received a wide range of support from beginners to professional users, and has been introduced with new features. In addition, the filler material can be removed with a single touch for easy maintenance. 2. The included pin allows you to connect with our bottom filter plate to enhance your filtration capabilities. 3. By connecting the "air pipe unit" (sold separately) (bottom filter common) to create a natural water flow inside the aquarium, preventing damage to goldfish caused by the discharge nozzle. 4. Cleaning the gravel on the bottom of the weights is now easy. 5. Of course, Plaston is designed to be used with a variety of cartridges including traditional replacement filler and activated carbon. Air lift type. *Please purchase the air pump separately. Comes standard with activated carbon cartridges; For aquariums under 11.8 - 15.7 inches (30 - 40 cm)