HQRP HEPA Filter for Eureka EF91B /&nbsp;EF91 / EF-91/67821 Replacement Upright Coaster HQRP HEPA Dust Cup Filter Replacement; This filter is H13 filtration class and retains 99.99% of particles down to 0.3 micron. 100% Compatible with Original filter; 2 weeks DOA replacement warranty!