* This filter is the 1st stage pre-filter used in the AlorAir Cleah Shield HEPA 550 Air Scrubber. * This MERV-10 Filter is made of synthetic fiber filter media. *  For MERV-10 Filters: Replace as necessary- we recommend checking the filters at least 1x/year. *  No modification of the AlorAir CleanShield HEPA550 Air Scrubber is required-users simply place the new MERV-10 filter and then re-secure the cover. This filter is the 1st stage pre-filter used in the AlorAir Cleah Shield HEPA 550 Air Scrubber. This MERV-8 Filter is designed for use in the AlorAir CleanShield HEPA 550 Air Scrubber. No modification of the AlorAir CleanShield HEPA550 Air Scrubber is required-users simply place the new filter. Changing the filters: 1. Loosen the 4 locks that hold the filter board in place. 2. Slide-out the filter panel board. 3. Remove the used filters and replace them with new filters.