The vacuum filter canisters keep clean dry air going into your blower. It also keeps any air particles water vapor oil based contaminants and other liquids from entering the blower which can cause damage to the blower and impeller. The particulates collected by the vacuum filter canister can be harmful to the motor and may cause over-heating. Features 2.5 Vacuum Filter Canister NPT Connection 850 CFMSpecifications Dimension: 9 H x 10 W x 11 L – SKU: ATBR099