The Fluval Pro Adjustable Air Diffuser (2-pack) is a set of versatile airstones that improve aquarium aeration. Each diffuser easily connects to standard airline tubing and is designed to operate quietly. Uniquely, they feature an adjustable flow control, allowing you to customize the bubble size and airflow for optimal oxygenation or gentle water movement. Compatible with all aquarium air pumps, these diffusers help create a healthier, well-oxygenated environment for fish.