Penn-Plax Standard Airline Tubing is durable, corrosion-resistant airline tubing designed to meet all your aquarium aeration needs. This standard-size 3/16” tubing will fit air pumps and air stones with standard fittings. It’s made to stand up to everyday wear, resists kinking and is safe for use in both freshwater and saltwater aquariums. You can also use this high-quality tubing for drip acclimation when adding new inhabitants to your tank. 25 feet long.