Features: Airline tubing: standard 3/16 '' diameter common to most airline accessories Air stones: durable and can produce fine bubbles continuously to diffuse oxygen efficiently in your fish tank Check valves: place these air pump check valves in your airline tubing between your air pump and aquarium water to prevent water returning down the air line Suction cups and T connectors: fit 3/16 inch ID standard airline tubing Package Includes: 14Feet Clear: 14feet clear tubing, 2 air stones, 2 check valves, 2 clear T connectors, 6 clear suction cups 14Feet Black: 14feet black tubing, 2 air stones, 2 check valves, 2 black T connectors, 6 black suction cups