Question edited for a lot more clarity.
Question moved from 'Filter Vacuums' to make model category.
Yes, that part number is listed for your model here
https://www.ezvacuum.com/hoover-40110001-43613021-selfpropelled-windtunnel-hepa-final-filter-generic-p-402.html
Hoover Filter High Efficiency Filter for Windtunnel Uprights. Fits Models: Hoover Self-propelled WindTunnel Upright vacuum cleaner models including U6420-900, U6423-900, U6425-900, U6425-920, U6425-950, U6431-900, U6445-900, U6445-906, U6445-920, U6449-900, U6450-900, U6451-900, U6451-960, U6455-900, U6455-960, U6458-900, U6460-900, U6470-900, U6470-910, U6471-900, U6474-900, U6476-900, U6476-910, U6431-900, U6432-900, U6433-900, U6434-900, U6435-900, U6436-900,
U6437-900, U6439-900, U6441-900, U6441-940, U6445-920, U6450-900, U6451-960, U6453-900, U6454-900, U6455-960, U6425-000, U6434900, U6436900, U6445-900, U6458-900, U6459-900, U6460-900, U6470-900, U6446-900, U6449-900, U6451-900, U6454900, U6471900, U6471-910, U6471-900, U6473-900, U5455-900, U6401-9RM, U64019RM, U6423-900. Measures app 10-7/16" x 3-5/16" x 1/2"
Quantity Per Package: 1 Hoover vacuum cleaner Final Filter
OEM Part Number: 40110001, 43613021, 40120101, FX-HVF067
Yours also seems to have its own standard filters not listed as HEPA.
https://www.appliancefactoryparts.com/vacuumcleaners/hoover/u6437-900.html
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