We used this to filter air coming in from outside. It fits an 18" x 12" x 1" air filter. Included are five MERV 13 air filters. We used it with air entering the through the bottom and out the top with the included short section of 5" flex duct directing the air flow where we wanted it. Does NOT include the blower.
In Ballard near the Goodwill store. Preference given to request with specific date and time for pickup.