High Quality Materials:The aquarium air stone is made of sturdy and durable sand stone and stainless steel material, been burned at high temperature, good air permeability, it is safe, washable and durable, non-toxic material to keep fish healthy and active, can be cleaned repeatedly and used for a long time. Unique Design: The bottom of the aquarium air diffuser is a flat bottom and the top is a semi-ellipse. This design of the hemisphere shape combined with the weight of the air stone can cause the air stone to produce much more bubbles and stably transport oxygen in water and promote air circulation in the water tank. Oxygen Aeration Stone: It produces even bubbles in water and increases dissolved oxygen, which can provide enough oxygen for fish and other aquatic organisms. Used in conjunction with an oxygen pump, the bubbles are evenly dispersed, and the effect of dissolved oxygen is good. Easy to Clean: Air stone disc can be used for a long time, just attach the air hose to the