Pure Enrichment Genuine 2-in-1 True HEPA Air Purifier Filter Target& more Go to product viewer dialog for this item.

: Look for "True HEPA" or "Absolute HEPA" on the label, which guarantees capture of 99.97% of particles at 0.3 microns . Be wary of "HEPA-type" or "HEPA-like" terms, which are unregulated .

A value pack including HEPA filters and carbon pre-filters for HPA100/200/300 series. Available at (~$63) and Target (~$65) . GermGuardian Air Purifier Replacement Filter B flt4825 Target& more Go to product viewer dialog for this item.

: Ensure the filter's Clean Air Delivery Rate (CADR) is at least 2/3 of your room's square footage for optimal efficiency .

: For general household use, HEPA 12 or 13 is standard. Sensitive environments or medical-grade needs often require HEPA 14 .

: Best for finding common replacement filters for mainstream brands like Honeywell and Holmes .

: Mechanical filters typically need replacement every 6–12 months, while carbon pre-filters for odor removal may need changing every 3 months . Air Purifier Buying Guide - Consumer Reports