Miele Hyclean 3D U Series SMS Bags Filter Set Pack Of 4 Plus 2 HyClean Dustbag with 3D Technology. Additional 20% more than our previous design Provides 9 layers of filtration, our HyClean bags retain more fine dust and small particles than a conventional dust bag Auto-shut mechanism which automatically closes the bag when the vacuum cleaner is opened, meaning you won't be exposed to unhygienic dirt. For the best results from your Miele vacuum cleaner, use these official Miele dust bags and enjoy performance and maximum efficiency. Suitable for S7 and Dynamic U1 upright vacuum cleaner models