The Miele AirClean 3D Efficiency FilterBags™ are equipped with an Auto-Seal™, self-locking collar that keeps microscopic dust and allergens safely trapped inside, so you never have to worry about releasing the lung-damaging particulates, dust and allergens you just captured back into the air, even during disposal. The New Soft Structure allows your vacuum to operate efficiently while using a lower suction setting. Miele Hepa Filters yield the highest ratings available for high efficiency particulate air. To qualify as HEPA by US government standards, an air filter must remove (from the air that passes through) 99.97% of particles 0.3 microns or larger.