【Compatibility】Only compatible with Purivortex AC400 Series AC400-Black, AC400-White Air Cleaner Purifier.The product dimension is 6.3 x 6.3 x 6.5 inch.Please check your air purifier model before you buy the filter 【3 Stage Filter】The AC400 replacement filter feature 3-in-1 filtration system including main filter,nylon pre-filter and activated carbon filter which can help to absorb most of pet dander,pollen and household odors. 【Value Pack】Including 4 Pieces of premium AC400 repalcement filters at low cost to save your money and bring you fresh air all at home efficiently 【East to replace】Just need to take off the plastic bag of the filter and install the filter into the ac400 air cleaner purifier without any tool.Besides, we recommended to replace the filter every 6-12 months depending on using frequency 【Why Choose our ac400 filter】Only using premium filter and cost you less than others.Besides,we will contact you immediately ,once you meet any question with our filter and contact with us in time, Filter