Blocked filters will reduce the suction in your vacuum cleaner. Cleaning and replacing your filters regularly will help to maintain its best performance. The high grade of material, used for this cartridge filter, provides your vacuum cleaner with a high filtration level and maximum dust retention. This filter fits the following cleaners: VELOCITY PLUS Z3040A/Z, Z3042A/Z series. We recommend that filters should be replaced at least twice a year or when they become visibly soiled.