Key Features Pack of 10 compatible biOrb airstones. High Quality materials that work effectively in the biOrb tank Suitable replacement for all biOrb filter systems. Recommended to replace ever 3-6 months Easy to replace, simply remove the Bubble tube to access the airstone, replace the airstone and reposition Bubble Tube Diffuses air into water supply reducing noise and large bubbles Essential to maintain oxygen saturation in biOrb Tank These pack of 10 compatible biOrb air stones are designed to fit with all biOrb aquarium filtration systems. It is essential to replace your air stones regularly, such as when showing signs of discolouration or a reduction in bubble rate. Replacing your air stones will ensure sufficient and clean oxygen for the aquatic life in your aquarium Compatible with all biOrb Aquariums Quantity: 10 Air Stones