The Pre-Evolution Sediment Filter (HydroLogic 22097) filters dirt and sediment from water, to prevent damage to your carbon Prefilter and reverse osmosis membrane. The sediment filter also reduces scale, rust and turbidity. Replace your HydroLogic 22097 filter cartridge regularly to ensure continual filtration and maximum efficiency of your system. The HydroLogic Sediment filter fits the Pre-Evolution Water Filter System. Reduces sediment and dirt for cleaner water. Adaptable to both city and well water (chlorinated and non-chlorinated sources). Helps maintain the integrity of your Reverse Osmosis System.