Aquarium Reef Reverse Osmosis - DI Water Reverse Osmosis Filtration System 4 Stage Reverse Osmosis designed for your Aquarium Reef.Clear Filter Housings. All quick connect push in type fittings. Assembled unit.Includes check valve on membrane housing permeate side. Color Coded TubingRed Tube: Feed Water with faucet diverter for easy connection to your kitchen faucet. Black Tube: Waste WaterYellow Tube: RO-DI Water product water Stage 1 - Sediment Filter 5 MicronStage 2 - Coconut Shell Carbon Block 5 Micron Stage 3 - TFC-2012-100 GPD RO MembraneStage 4 - DI - Color Changing indicator Filter All filters/membrane are industry standard size Most items ships within 1 business day Returns are only accepted provided item is returned in original condition. Used or installed items are not accepted for return. Water World Systems