Feature: 1. Made from high quality ore material, environmentally friendly, and stable. 2. Help to dissolve more oxygen, increasing the amount of oxygen in the water. 3. Ideal for creating many oxygenating bubbles within your aquarium. 4. Easy to use, simply connect airline and air pump to the bubble stone, and place in the aquarium 5. Calabash shaped bubble stone design, unique and fashionable, perfect for decorating any fish tank. Spec: Condition: 100% Brand New Material: Ore Color: Random Quantity: 10pcs Fitment: 4mm Standard Interface Diameter: Approx. 2cm/0.79in Weight: Approx.70g/2.47oz Package List: 10 * Bubble Stone Notes: 1. Please allow minor error due to the manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly difference from the real object. Please take the real one as standard.