Boyu WM-Series Flow Pump (WaveMaker) Features: Patented impeller structure: slow flow and turbulent flow, which solves the defects of common pump flow mode and flow rate too fast. For you to create marine life - a natural and ecological environment. Swivel angle adjustment, implemented in any suitable direction of water flow, handsome in appearance-power low-flow side large variety of installations allows the user to use; Model Model Suitable Aquarium Size WM-101 7W 20-120L 85x78x84mm WM-15 16.5W 80-350L 113x108x110mm WM-1 28W 40-300L 113x108x110mm WM-2 18W 40-260L 113x108x110mm WM-3 4x28W 100-600L 113x108x110mm