Check the listing for details. Original Koolermax KPAK-3 Replacement Sediment Carbon Block Filter AR122 HK120. Condition: New. Listed at 44.00 USD. KoolerMax Series replacement filter kit for Model: AR-122, HK-120, HK-220 High capacity, replace every 12 month, Part no. KPAK-3 To view a list of replacement filters for KoolerMax RO system, go to KoolerMax.com Store and click on Replacement Filters 1st stage: high capacity, multi-layer 5 micron sediment filter, to remove sediment, rust, sand, (replace every 6-12 months) 2nd stage: high capacity carbon filter, carbon block, coconut shell activated carbon removes chlorine, taste & odor (replace every 12 months) * We have modified the filter from granular to carbon block for higher performance. 3rd stage: high capacity carbon filter, carbon block, coconut shell activated carbon further removing chlorine to ensure 100% removal of chlorine (replace every 12 months) * We have modified the filter from granular to carbon block for higher performance. If you have questions about this item please feel free to email us. Our business hours are M-F 9am to 4pm PST.