High Performance Air Filter: This filter effectively and efficiently filters the air that passes through the vacuum cleaner to that it traps particles before they re-expel the air. High Efficiency Particulate Air Filters (HEPA) are a type of filter that can remove at least 99.97 % of dust, mold, pollen and any other airborne polluting particles with high efficiency. Easy to Clean and Install: Unlike other types of filters, this filter is not easily blocked. When it's time to clean it, simply shake the excess powder in a container and then wash the filter under running water. Let it air dry thoroughly before putting it back in the vacuum cleaner. To add this replacement filter to your vacuum, simply remove the old filter and twist it into place. Good Fit: For CM300S CM400 CM500 CM800 Wireless Vacuum Cleaner, helping your vacuum cleaners to perform at their best again. Beneficial for allergy sufferers: Often the particles that are collected by a vacuum are microscopic and not visible to the eye. However, even the smallest particles can irritate the nose, throat, or lungs, especially for anyone with allergies or asthma. Without realizing that some vacuum cleaners can disperse them back into the air. This HEPA filter traps almost all particles and prevents them from re-floating in the air. Tips: The filter can be washed under running water and must be completely dry before reinstalling. Replace the pre-filter every 6 months and the filter every year for optimal cleaning performance. Replace or clean your filters regularly for optimal performance.