Submersble UV-C lamps have a big advantage compared to conventional UV-C units: no pressure loss!
These lamps can be used in filter tanks so the water can pass without any resistance/pressure loss.
NOTE: the UV-C radiation range is limited (dependant on i.e. the water clarity) so only a part of the water flowing by is treated. The user himself is responsible for the dangers of exposure to UV-C radiation to the eyes! Use the supplied safety glasses and/or a safety switch that automatically switches the lamp off when you have access to the lamp.
Warning: Please be sure the lamp is always completely under water!