This type completely encloses the futon in a bag and then fills it with high-temperature air from a futon dryer. This futon drying bag eliminates over 99% of dust mites. Effectively eliminates dust mites with high-temperature air of 50°C or higher. Used only 1-2 times, it's practically new. Compatible with Iris Ohyama futon dryers: "Kararie" High Power Twin Nozzle. You can get an idea of how to use it from the 3rd and 7th images. - Brand: IRIS OHYAMA - Product Name: Dust Mite Elimination Futon Drying Bag for Futon Dryer - Features: Eliminates over 99% of dust mites - Temperature Setting: Hot air of 50°C or higher - How to Use: Use in a sealed space