FZ-D50HFF filter set for humidifying air purifiers, including pre-filter and HEPA filter. I opened it intending to replace it, but I made a mistake with the model number and am listing it for sale. I realized my mistake after opening it and immediately stored it in a zip-lock bag, but please refrain from purchasing if you are concerned about this. - Model Name: FZ-D50HFF FZ-D50DF - Application: Filter for humidifying air purifier - Filter Type: Pre-filter - Filter Type: HEPA filter Thank you for viewing.