HQRP Cartridge Filter 2-Pack for Shop-Vac 16RT500A 16RTP550A 4040H 4045AH 85L450 85L575 Vacuum Cleaner Coaster HQRP&reg; Two Cartridge Filters Replacement plus HQRP&reg; Coaster; HQRP filters are washable and reusable! This PP compound filter is H12 filtration class and retains 99.97% of particles down to 0.3 micron; 100% Compatible with Original filter; 2 weeks DOA replacement warranty!