Two major functions: There are water bubbles and decorations. Save time and money. If you want a foaming effect, You can connect the air hose and the air pump Little fish house: It has 6 caves where your love fish can hide and create a natural atmosphere and happy for your fishes safe and non-toxic: The aquarium decoration is made of polyester resin, which is safe and BPA-free and is not harmful to your fishes and aquariums. Please feel free to use Widely used:Because the fish tank decoration is made of polyester resin, it has high salt water resistance, so you can use it in freshwater and saltwater aquariums