Most conventional carbon filters only filter certain substances from your water. This ZeroWater patented Ion Exchange System filter, with five combined technologies, provides the only filtered water that meets FDA definition for purified bottled water. Stage 1 – Activated carbon infused micron cloth. Stage 2 – Multi-layer system using activated carbon & oxidation reduction alloy. Stage 3 – Distributor that maximized contact. Stage 4 – Comprehensive ion exchange array. Stage 5 – Non-woven membrane to remove fine particles. Filter life is based on water consumption & inlet water quality. Each filter has perforations to help speed the filtering process & avoid potential cases of air lock in the water flow. Filtering your water through these ZeroWater filters improves the healthfulness & taste of your tap water. It also prevents you from throwing plastic water bottles into the trash & clogging up landfills.