General description Suitable for both freshwater and saltwater aquariums and hydroponics, this 4-Pack 6-Inch Aquarium Air Bar is designed to enhance the dissolved oxygen content in your tank. These air stones create beautiful bubble walls that not only add aesthetic appeal but also improve aeration and water circulation. Technical specifications Shape: rod Material: mineral, plastic Outlet connection diameter: 5 mm Max. stone length: 15 cm Overall dimensions: approx. 16.5 x 2 x 1.3 cm Color: green and blue Contents 4 air stones for aquariums