Good filtering: Aquarium increase oxygen into the environment, bio farming increase oxygen. Adopts sandstone, through high temperature agglomeration, good gas dispersion, good filtering, ozone resistance, corrosion resistance. 
Increase oxygen: Live fish and seafood transport increase oxygen. Can increase oxygen content, reduce carbon dioxide, and increase acidity alkalinity can produce water. 
Bubble stone: Bubble stone Commonly known as diffuser stone, a durable, good aeration, filtration, and widely used: A sewage treatment plant for aeration and stirring to prevent large particles of sediment deposition, and removal of some organic matter. 
Purification: Aquarium (purifiers) purification, filtration and water quality ozone sterilization and aeration. Important tool for maintaining the respiration process of fish in aquarium. 
Perfect accessories :small size and lightweight, sturdy, durable and long service life. Can be widely used in a variety of places, perfect accessories for aquarium. 
Comes as a 2pack.