This professional aquarium Air Stone, made of premium acrylic material, is durable and practical with . This Air Stone is simple and great way to add oxygen to your aquarium, fish tank, hydroponic and circulation system. Great for fish tank and aquarium use. Good for maintaining the health of your pet , make their daily life more happy. Features -Color:Multi -Material:Acrylic -Size:7.50X7.00X4.30cm/2.95X2.75X1.69in - Durable and useful, great for home, office fish tank, aquarium and hydroponics nutrient tanks. - Simple appearance design, delicate and smooth, and the bubble output is more even. - Maximizes the outlet area of the air stone to provide a larger area for bubbles, quiet and useful. - Add beauty to your display aquarium with this Air Stone to create nano bubbles to add oxygen. - Produce fine bubbles for oxygen replacement, useful and excellent, lightweight and small size. Package list: 4 x Air Bubbler Disc 4 x Regulator