Bought as a replacement for the original Juwel internal filter on the external filter Sera Trigon 190 250 + UV. To accelerate the biological filtration new filter material was mixed with existing material. Filter runs well, is easy to clean and has a much longer service life than the inner filter. Furthermore, only three different filter media in use, of which only the upper fine filter is occasionally washed or cleaned. At the beginning of annoying loud the filter has, however, surprisingly far calmed after 4-6 weeks. Now he no longer interferes (in the cabinet), and the UV lamp has remained well intact. Had already Eheim External filter in use, were not handled better or quieter. Conclusion: good evasive articles on Eheim, JBL, etc ..