The H2O+ Circle Triple Filter Replacement Pack includes the Sediment, Pre-Carbon Plus and Post Carbon Block filters. These three filters together with the RO Membrane filter reduce harmful VOCs, chlorine, fluoride, heavy metals, cysts, industrial chemicals, bad taste and odour in the water. The filters are simple to replace with the easy twist and seal system. The LED filter change indicator included in the provided faucet will let you know when it's time to change the filters. Recommended triple filter replacement is every 6 months.