Material: Sand stone + ABS_x000D_ Diameter: 10cm_x000D_ Height: 2cm_x000D_ Color: black + gray_x000D_ Shape: Disc shape_x000D_ Purpose: Suitable for fish tank size 70-120cm_x000D_ Applicable scope: Applicable diameter is 4mm inner diameter hose 1High-temperature sintered air stone is made of high-temperature sintering, which is different from the general commercial air stone. 2_x000D_ The durable air stone can disperse water in any direction to form a beautiful underwater scene. 3_x000D_ Increase surface agitation. 4_x000D_ Accelerate oxygen supplementation and provide other health benefits for fish. 5_x000D_ Help release carbon dioxide accumulation. 6_x000D_ It can be used for a long time and is easy to clean for repeated use. 7_x000D_ Instructions for use: 8_x000D_ 1. Please use a trachea (not included) to connect the air stone, and connect the other end of the trachea to an air pump (not included). 9_x000D_ 2. Please soak this product in water for 15 minutes before use. 10_x000D_ 3. Long-term use, if the dirt is blocked and the bubbles are reduced, it can be taken out for cleaning and used repeatedly.If you find that there is no air out of some places when this product is used for the first time, the air pump you are using is not enough. Please replace it with a more powerful air pump.1*Aquariums Oxygen Stone