Eureka HF-9 HEPA Filter, 1-Filter for Models 60285, 60951 and 28455 EUREKA Boss Widetrack, Whirlwind and Whirlwind Lite (4100, 4300-4600, 5180, 5190, SC4180, SC4500 Series) Uprights HEPA filters capture 99.97% of particles down to .3 microns in size Ultra-Fresh treated filters provide advanced protection from odor causing bacteria Ultra-Fresh treated filters are guaranteed from defects