This Shop-Vac Dry Filter with Mounting Ring must be used with a 90585 foam sleeve. Save money & another trip to the local store with these economical, reusable disc filters. These filters fit most Shop-Vac brand wet dry vacuums 5 Gallon & above. Comes in a package of 3 with easy to use mounting ring for pick up of larger debris & dry material. Wash & reuse.