For HV321, you need these: https://www.ezvacuum.com/shark-rocket-pre-motor-filter-1080ftv320.html and https://www.ezvacuum.com/shark-rocket-post-motor-filter-1084ftv320.html
Free Shipping on all US Ground orders
For HV321, you need these: https://www.ezvacuum.com/shark-rocket-pre-motor-filter-1080ftv320.html and https://www.ezvacuum.com/shark-rocket-post-motor-filter-1084ftv320.html