CuZn 5 Stage, 50GPD Reverse Osmosis Replacement Filter Bundle with Membrane (Universal 2.5" x 10" Drop in Style Cartridges) All filters are NSF Certified & 100% Lead Free, Universal Fit (2.5" x 10" Slimline Series Filters) Stage 1: High Quality 5 Micron Sediment Filter Stage 2 & Stage 3: 5 Micron Carbon Block Cartridge Stage 4: 50 Gallon Per Day Reverse Osmosis Membrane Stage 5: Post Membrane Taste & Odor Polishing Cartridge with 1/4" Quick Connect Fittings "Push Fittings" on the Inlet/Outlet. Looking for a Complete New 5 Stage Reverse Osmosis System? Search ASIN#B019N7VG1W