The PAK600 is the OEM one-year filter kit for the Abatement Technologies CAP600 central air purification system — everything your system needs to maintain full filtration performance for 12 months, in one order. What's Included F621 Pre-Filter15 1/2" × 16" × 1" | MERV 4 12 filtersReplace one per month VL602 Second Stage Carbon Filter15 1/2" × 16" × 2" pleated | MERV 6 | activated carbon 2 filtersReplace every 6 months Replacement Schedule Monthly: Swap one F621 pre-filter — protects the second stage and HEPA filter from coarse particulate load Every 6 months: Replace the VL602 carbon filter — maintains odor capture and prevents carbon saturation Every 3 years: Replace the H610C-99 HEPA filter (sold separately — see note below) HEPA Filter — Sold Separately The PAK600 does not include the H610C-99 HEPA filter. Abatement Technologies recommends replacing the HEPA filter every 3 years under normal operating conditions. On your third annual order, add the H610C-99 HEPA filter alongside your PAK600 to stay on the full manufacturer-recommended maintenance schedule. All filter media in the PAK600 are UL 900 Class 2 listed. OEM components from Abatement Technologies — sized and specified for the CAP600, guaranteed fit.