Aftermarket replacement for Whirlpool Carbon Pre-Filter for Models AP350, AP450, AP510 (4-pack) Fits Whirlpool air purifier models AP300, AP350, AP450 and AP510 Helps remove household odors including: smoke, cooking and pet odors Direct replacement for Whilpool 8171434 and 8171434K filter includes mounting tabs Aftermarket 4 Pack By Breathe Naturally Made in the USA From BulkFilter Brand Filters