The Air-Tech Aquarium Air Pumps by Penn-Plax are quiet, reliable solutions for aerating and oxygenating fish tanks. Whether you have a small tank or a larger aquarium, these pumps provide constant airflow, ensuring your aquatic pets thrive in a well-oxygenated environment. These pumps are available in two models to suit different tank sizes, the AT2K2 ideal for tanks up to 20 Gallons and AT2K4 suitable for tanks up to 65 Gallons. Both models ensure constant airflow and work with freshwater and saltwater aquariums. Each pump is designed with a rubber armature, silicone polymer flappers, rubber feet, and a thick plastic cover to reduce noise, making them ultra quiet pumps.