This deluxe three layer WindTunnel Primary Filter fits in the bag chamber below the paper bag. It consists of a white screen, a yellow filter layer and a green filter layer. The filter measures 5" x 2 3/16" x 3/8" with a rectangle notched out of the one corner. Hoover has replaced this filter with the WindTunnel Primary Filter #38765019.   For similar products see our list of current Hoover Vacuum Supplies.