Features: Create a soothing water Flowing and reduce noise, ensuring a peaceful environment for both fish and enthusiasts. With a unique noise reduction designing, maintaining a clean aquarium. For home aquarium hobbyists want a better and efficient tool, as well as professional aquarists want to improve the health and happiness of their fishtank. Perfect for use in various setting such as home fish tanks, commercial display aquariums, and so on... With better water flowing management, making it great accessory for aquarium enthusiasts. Specifications: Component:ABS Inner Diameter S: Approx.20mm/0.79inch Inner DiameterM: Approx.25mm/0.98inch Inner Diameter L: Approx.32mm/1.26inch Quantity: 1pc/ 3pcs Package Includes: 1pc/ 3pcs FishTank Outlet note: 1.Please allow 1-2cm errors due to manual measurement, note that you donot mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual color.