【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 air inlet and place it where you want.If the oxygen is reduced, you just need to gently brush the surface of the bubble stone with a brush. 【Widely Used】 Air Bubble Stone is very suitable for use in freshwater, saltwater aquariums, hydroponics or in fish farms, aquatic cultures. It is not only practical, but also pleasant.creates amazing beautiful underwater scenes. Just connect the aquarium air pump. The air stones are made of high quality non-toxic mineral material. With high temperature sintering, the stones are sturdy and durable, have high dissolved oxygen, and produce uniform and tiny bubbles instead of a limited number of large bubbles. Features: 1.Weighs enough to sink into the ground without suction cups. 2.Dissolve more oxygen in water.Create quiet, smooth, dense small bubbles in water.Strong filtration for fresh and salt water. 3.Clean them regularly with a brush as they get clogged after weeks or months of use. Replace the stone once it stops working properly. Specification: Condition: 100% Brand New Item Type: Bubble Stone Material: Mineral sand stone + stainless steel Colour: blue-grey Bottom diameter: 6 cm Package includes: 1 * for Aquarium Air Bubble Directions: 1. Connect the air hose to the air stone 2. Soak the air stone in water for 15 minutes before use 3. Turn on the air pump switch to use Note: 1.Soak the product in water for 15 minutes before using. 2.Please allow 1-2cm error due to manual measurement. 3.Due to the light and screen setting difference, the item's color may be slightly different from the pictures.