Interpet Goldfish Bowl Filter Starter Kit. This kit includes an air pump that creates a flow of bubbles, which pulls water through the gravel at the bottom of the bowl where waste material is trapped by beneficial bacteria. The kit contains 1 X Aqua Air Mini with Instruction Leaflet, 1 X Check Valve, 1 X Round Airstone 7/2, and 1 X Airline Tubing 1M.