Be confident in your purchase we're an Authorized AquaIllumination Dealer. How cool is that?!?!? AXIS 20 Specs: Max Head: ?5ft (?1.5m) Flow Rate: ?185gph (?700lph) Power Consumption: Variable, 12W max Recommended Tank Size: Up to ?15 gallons AXIS 40 Specs: Max Head: ?9ft (?2.8m) Flow Rate: ?400gph (?1500lph) Power Consumption: Variable, 20W max Recommended Tank Size: Up to ?40 gallons AXIS 90 Specs: Max Head: ?10ft (?3m) Flow Rate: ?925gph (?3500lph) Power Consumption: Variable, 40W max Recommended Tank Size: Up to ?90 gallons Nozzle Sizes (Barbed): Axis 20 Small: 0.5in. 12mm Large: 0.625in. 16mm Axis 40 Small: 0.625in. 16mm Large: 0.75in. 20mm Axis 90 Small: 0.75in. 20mm Large: 1in. 25mm AI Aquaillumination Axis Centrifugal Aquarium Water Pumps offer full control, wireless smart device programming, DC motor quiet operation, and output calibration. Features that have traditionally been reserved for considerably larger and more expensive pumps. These features allow for: Coordinate Feed/Maintenance Modes- Turn all of your AI pumps on or off with a control button on a single pump. Prevent back-siphon- With calibration set, instead of powering off, a pump will continue to run without producing flow, preventing siphoning, which could result in air bubbles when the pump resumes its scheduled operation! With Axis you get exactly what you need, starting with Axis 20 which is perfect for tanks 15 gallons or less.