HQRP Washable Dust Cup Filter 4-Pack for Eureka Optima 431 431A 431BX 431F 431DX 433 433A 437 437AZ, Pet Lover Oh! 439 439AZ Vac Vacuum Cleaner Coaster HQRP&reg; 4 Filters plus HQRP&reg; Coaster; This filter is HEPA filtration class H12 and retains 99.97% of particles down to 0.3 micron. HQRP filters are washable and reusable! Compatible with Original filter; 2 weeks DOA replacement warranty!