The Shop-Vac foam sleeve part number 9058500 is used for picking up wet messes and is required when using reusable disc style filters. This foam sleeve fits most of the Shop-Vac utility wet or dry Vacuums. The foam filter must be installed unless a cartridge filter is installed. The Shop-Vac foam filter is compatible with most Shop-Vac utility wet or dry vacuums 5 gallons in size and larger.For picking up wet messes when used aloneRequired when using reusable disc style filters8 in. diameter and 6.5 in. high approximate size of sleeve