Blocked filters will reduce the suction in your vacuum cleaner. Replacing your filters regularly will help to maintain its best performance. The high grade of material, used for our filters, provides your vacuum cleaner with a high filtration level and maximum dust retention. This kit includes 2 micro filters for the following cleaners: BOSS CYCLONE Z4385, CYCLONE POWER LITE Z4393, CYCLONE POWER PLUS Z4645. We recommend that filters should be replaced at least twice a year or when they become visibly soiled.