Compatible For Germ，Compatible for Guardian，FLT4825 Three-layer composite filtration: H13 pre-filter, which effectively captures fine particulate matter. High capacity and long-lasting: Under normal household conditions, it can hold dust for 2 to 3 months, reducing the frequency of replacement. Installation and removal: Precisely sized to fit most mainstream air purifier models, it can be easily installed and removed by hand without tools. Wide compatibility: Suitable for most household air purifiers.