The microfiber material in this bag provides clean air during vacuum cleaning. The filtering in the new 4-layer bag is significantly improved, approximately three times more than an ordinary paper bag. The microfiber material gives your vacuum cleaner more suction power, allowing you to fill up approximately 33% more dust in the bag without affecting the suction quality. The fiber bag has the DIN 44956 test. Contents: 5 pieces + 1 filter. Fits: Bosch Siemens.