Betta AP Silent Aquarium Air Pumps are recommended for use in indoor aquariums. Suitable for use with standard 4/6mm airline and compatible accessories such as Betta Air stones, Air Curtains, air-operated aquarium ornaments, plus under-gravel and other air-driven filters (not included). They are great for increasing the oxygen levels in your aquarium. 4 models available, to suit aquariums up to 200L.