Check the listing for details. 10pcs Fish tank oxygenation pump air stone large size quartz sand bubble stone. Color: blue, Condition: New. Listed at 14.79 USD. Product introduction:Product Name: fish tank oxygenation pump gas stoneProduct diameter: 2.2cmProduct height: 4.5cmProduct weight: 25.4gProduct material: QuartzProduct features:1. This product is made of quartz, strong and durable, and the bubbles produced are small and dense.2. The surface area and volume of the gas stone are more than twice that of the common bubble stone in the market, with larger air outlet and more bubbles.be careful:1. Please soak in water for 15 minutes before use.2. If the bubbles become less after long-term use, it may be because the surface is blocked by stains. It can return to normal after taking out and cleaning.3. If there are few bubbles, it may be that the power of the oxygenation pump is not enough. Please use a higher power oxygenation pump.4. Suitable for connection with 4mm oxygenation pump hose.Quantity: 10pcs