Light weight Gascolator for smaller engines like Rotax912. It filters the gasoline and separates water which is probably condensed in the tank . The red indicator is normally on the ground of the transparent reservoir. If water has been separated the red inicator will swim in the water and indicate the level of water in the reservoir. So you can check before each flight if you have risk with water. In same cases you get some water in fuel from the fuel station. With this device you have the chance to find out the reason if your engine shows problems due to water in fuel. It works best, if it´s at the deepest level of the fuel system. The device has the fluid resistance of standard fuel filters. Anyhow you should check the compatibility with your fuel system. We would not recommend to use both, the standard fuel filter in series with the gascolator, because then you will have additional fluid resistance. Remark: The use of the gascolator is under full responsibility of the buyer. New filters are available as spare Part. Empty wight only 80g !!!