Home Revolution Replacement Carbon Pre Filter, Fits Whirlpool AP300, AP350, AP450 & AP510 Air Purifiers and Parts 8171434K Designed to fit:Whirlpool AP300, AP350, AP450 & AP510 air purifier models, compare to Whirlpool part # 8171434K Replace with confidence: We back all of our products with a 100% satisfaction guarantee Breathe easy: Carbon pre filter removes even the smallest particles of allergens, impurities, and odors from the air and refreshes your home The Home Revolution Mantra: High-quality replacement products at a low price What you get: 4 carbon air purifier pre-filters