Check the listing for details. Aquarium Air Pump 20 Gallon Air Bubbler Small Air Pump with Airline Tubing Stone. Condition: New. Listed at 8.99 USD. Features: Ÿ The small aquarium air pump puts out a nice consistent flow of bubbles for fish to swim through and keeps the water oxygenated. Ÿ This nano fish air pump works with a small air stone, sponge filter, air bubbler decoration, or other bubble ornaments for a small fish/shrimp tank or hydroponic system. Ÿ The mini fish tank air pump creates a steady stream of air for small a betta tank, brine shrimp hatchery and small hydroponic setup. Ÿ 4 rubber feet at the bottom keep it from sliding around to reduce the noise further. Ÿ The check valves would protect you air pump by preventing aquarium water from back siphoning during a power outage when your air pump is below the tank water level. Specifications: Ÿ Recommended Tank Size: 20gal. Ÿ Dimension: 4x2.75x1.5 inches (L x W x H) Ÿ Length of power cord: 2.5 ft Ÿ Voltage: 110V-120V/60Hz Includes: 1x Air Pump 1x 3.3ft Tubing 1x Check Valve 1x 1” Air Stone Directions for Use: Ÿ Cut the tubing to the length needed. Ÿ Attach the airline into the pump; connect the air stone to the other end of airline. Ÿ Place the pump above the aquarium or bucket if possible. Or you need to add a check value (the blue valve) between air pump and air stone to prevent back siphoning. Ÿ Plug the pump in. Remember to make a "drip loop" for the power cord.