Universal 5 stage Reverse Osmosis Replacement Filter set with 75 GPD membrane, USA Universal Replacement Set for Undersink 5-Stage Reverse Osmosis Water Purification Systems Stage #1: 10" Sediment Filter, 5 Micron. Removes dirt, silt, sand, rust and scale particles. Stage #2: 10" 10" GAC Granulated Activated Carbon Filter. Removes chlorine, chloramine, VOCs and etc. Stage #3: 10" CTO Carbon Filter. Removes chlorine, chloramine, VOCs, bad taste and odor, 5 micron Stage 4: High Rejection 75 GPD membrane, Stage 5: 5 Micron Inline filter with T33 carbon, made Omnipure USA (CLIROT33)