Hoover # 38765019 / 38765023 secondary vacuum cleaner filter. Fits most WindTunnel self-propelled models. This filter fits inside the Hoover WindTunnel bag chamber. Original filter manufactured by Hoover is No Longer Available.  Filters shown are maufactured by Envirocare.

Fits but limited to the following Hoover upright vacuum models:C1701900, C1703900, C1705900, U5140900, U5145900, U5146900, U5148900, U5150900, U5155900, U5156900, U53019RM, U53029RM, U5348911, U5402900, U5409955, U5416900, U54219RM, U5435906, U5436950, U5438960, U5453900, U5458900, U5458910, U5460900, U5462900, U5467900, U5468900, U5470900, U5473900, U5481980, U5491900, U5491950, U64019RM, U6420900, U6434900, U6436900, U6445906, U6454900, U6471900, U6476900, U6476910, U6485900, UH30015, UH30030HD, UH50000.