Description: (SM042) Features Effective Surface Skimming Safe for small Shrimp and Fish Easy Cleaning Adjustable flow rate Adapts to water level changes Multi-directional flow outlet Max flow rates from 50-200L/Hr Power: 3watts Size: 4.5x6x13.5cm tall The aquarium water surface may develop unsightly oil slicks due to fish waste, uneaten food and dirty air. Oil slicks reduce the amount of gas exchange at the waters surface and the air above which will reduce the amount of oxygen in the water. Oil slicks also cause reductions of light penetration into the water. The Ocean Free Surf Clear Aquatic Surface Skimmer can effectively remove any oil slicks and keep the water surface clean and clear.