Grizzly G0548ZP 2 HP Canister Dust Collector with Aluminum Impeller - Polar Bear Series With the canister filter, simply turn the handle on the top a half turn in either direction to cleaning the canister The handle controls three cleaning flappers inside and shakes the dust from the filter letting the fine dust fall directly into the collection bag The canister filter is made of spun bond polyester with 1 micron filter capacity