Features: 1. Six sizes for your option: Diameter 20mm(0.78in),25mm(0.98in),30mm(1.18in),40mm(1.57in), 50mm(1.96in) for your options,fit for different size of tank. well-constructed for continual bubbling. Ideal for fish tanks, aquariums and small ponds. 2. Bubble diffuser: The air stone ball produce a good amount of dense bubbles. A great way to increase oxygen solubility in your aquarium and enliven the aquatic lives. 3. Ball-shaped design: makes it easily be hidden in your aquarium or other fish tank bubble decorations 4. Reliable Material: Made of mineral material and sintered at a high temperature, it causes no effect to the health of your aquatics. Keep fish or roots growing healthily. 5. Easy to Use: Soak the stone completely in water for 1 hour before use. Clean it regularly with a brush as it gets clogged after weeks or months of usage. Specifications: 1. Size: 20mm(0.78in),25mm(0.98in),30mm(1.18in),40mm(1.57in),50mm(1.96in) 2. Color: Grey
