The sera hoses are suitable for all common filters and pumps with a corresponding connector. They are free from harmful substances and very elastic for a safe connection to the aquarium.Sera Aquarium hose green+ hose for air and water applications+ green-transparency coloure+ in different sizes available+ order the needed quatitiy, price is by the meterAvailable in the following sizes: The price is per one meter.sera aquarium hose 4/6 mm, maximal length in one piece is 200 msera aquarium hose 9/12 mm, maximal length in one piece is 70 msera aquarium hose 12/16 mm, maximal length in once piece is 50 msera aquarium hose 16/22 mm, maximal length in once piece is 25 m