EnviroCare Replacement Pre Motor Filter for Hoover WindTunnel Air Uprights This is the foam type washable primary filter for the Hoover Windtunnel Air Bagless Upright model UH70400, and UH70405. This filter is located directly underneath of the Dust Cup Lid, and should be washed every 30 days to ensure peak performance of your WindTunnel Air. by Envirocare #f652