Air Purifier Pre-Filters Compatible with Honeywell HRF-AP1, Filter A (Makes up to 8 Filters). Universal Carbon Pre Filters. <p> Replaces old pre-filter model 38002. <p>This pre-filter can be used in a variety of Air Purifiers. Each large pre-filter can be cut to make 1-8 pre-filters depending on your particular model. It is common for users to measure, or use the old pre-filter as a template, to cut the new pre-filter to the correct size. <p>Packaging may vary.<p> This is NOT a Honeywell OEM product. The Honeywell brand names and logos are the registered trademarks of their respective owners. Any use of the Honeywell brand name or model designation for this product is made solely for purposes of demonstrating compatibility.