This is a high efficiency 4 PK Whirlpool Carbon Pre-Filter. This 4-Pack Features a Carbon-based filter which is Designed to Fit Air Purifier Models: AP300, AP350, AP450 and AP510. Compare to Part # 8171434K. This is a generic product designed and engineered in the United States by Crucial Air. This is not a Whirlpool OEM product and is not covered under any Whirlpool manufacturer's warranty. The Whirlpool brand names and logos are the registered trademarks of their respective owners. Purchase of this product voids your Whirlpool warranty. Any use of the Whirlpool brand name or model designation for this product is made solely for purposes of demonstrating compatibility.