This Beurer three-layered filter set makes your Beurer LR220 air purifier work perfectly. The filter set with 99,95 % filter performance contains 3 filters. The prefilter removes domestic dust hairs, small insects. The activated carbon filter removes harmful gases, VOC, different smells. The HEPA filter class 13 removes various bacteria and viruses, mites, fine dust, pollen. If you wish to change the combi filter at specific personal intervals (e.g. every six months), there is a sticker on the upper edge of the combi filter on which you can enter the date installation and changed date. Regular cleaning of the filter (once a month) is essential for hygienic and fault-free operation: Clean the three-layered filter using the brush attachment of a vacuum cleaner. Along with the regular cleaning of your air purifier, you should also change the filters regularly. After 4260 operating hours, the red "Filter reset" LED flashes on display.