HQRP 2-pack Foam Filter Sleeve for Shop-Vac Wet/Dry Vacuums, 9058500/905-85-00/90585 Replacement Coaster HQRP&reg; Foam Filter Sleeve + HQRP&reg; Coaster; Use on filter cage for vacuuming water, for picking up wet messes when used alone. Also required when using reusable disc style filters. Replaces Shop-Vac Foam Filter Sleeve Part # 9058500 / 905-85-00 / 90585. Required unless you are using a cartridge filter. 100% Compatible with Original filter. 2 weeks DOA replacement warranty!