Aquaneat Aquarium Airline Tubing Feature: Standard 3/16" diameter fits all standard outlets, including air pumps, check valves, filtration system, air stones, air flow control valves, and aquarium ornaments Soft, pliable tubing will not harden; Resistant to CO2 corrosion Remains ...Aquaneat Aquarium Airline Tubing Feature: Standard 3/16" diameter fits all standard outlets, including air pumps, check valves, filtration system, air stones, air flow control valves, and aquarium ornaments Soft, pliable tubing will not harden; Resistant to CO2 corrosion Remains kink-resistant for long periods and blending better with aquarium decor Safe for salt and freshwater aquatic environments Includes: One piece of 25 feet airline tubing One piece of 25 feet black airline tubing Standard 3/16" diameter fits all standard outlets, including air pumps, check valves, filtration system, air stones, air flow control valves, and aquarium ornaments Soft, pliable tubing will not harden; Resistant to CO2 corrosion Remains kink-resistant for long periods and blending better with aquarium decor Safe for salt and freshwater aquatic environments