The listings describe multi-stage filtration: a pre-filter (or carbon pre-filter) for larger particles like hair and dust, an activated carbon layer for odors and smoke, and a HEPA-style filter rated to capture particles down to 0.3 microns.
Product details recommend replacing the filters every 6 months to maintain effectiveness and efficiency. (Actual replacement frequency may vary with usage, air quality, and manufacturer guidance.)
Listings state the filters capture particles 0.3 microns and larger and list common targets such as pollen, household dust, smoke (including tobacco and wood-burning smoke), odors and smog; some listings also mention VOCs and pet odors.
Product details list polypropylene (filter media) and activated carbon as the primary materials used in these replacement filters.
Listings state the HEPA filters remove up to 99.97% of airborne particles as small as 0.3 microns, and that they capture particles 0.3 microns and larger.
The product descriptions explicitly state these are not Holmes OEM filters and are not endorsed by Holmes; the Holmes name and model numbers are used only to indicate compatibility.
Listings describe installation as easy: remove the old filter and insert the new one — no tools required.