Eureka filter HF-8 is also known as the MM Eureka HEPA filter.
The HF8 / MM filter fits canister Eureka and Sanitaire 3670, 3684, 3685, S3681, SC3683, S3686 and 3695 series vacuums.
Eureka universal replacement filter part:
Eureka Mighty Mite Pet Lover model 3684F vacuum is an example of a canister vac that uses the HF8 / MM filter.
Replace Eureka HF8 filter every 6 months for to maintain optimal filtration performance.