xActual filter label may change depending on stock High capacity filter replacement cartridge pack for most standard 5-stage RO systems. Reverse Osmosis Membrane (Replace once a year) - The reverse osmosis membrane is a thin film composite membrane that can remove up to 99% of over 1, 000 contaminants in the water, including lead (removes up to 98% of lead), chlorine, fluoride, arsenic, asbestos, calcium, sodium, and more. Sediment Filter (Replace twice a year) - The Sediment Filter works as the first barrier in the Reverse Osmosis System, removing solid particles like silt, rust and dirt from the water and reducing a significant percentage of contaminants in the water. It prevents the other filters from getting clogged with fine particles and reduces the risk of damages to the other components. Granular Activated Carbon Filter (Replace twice a year) - Activated Carbon filters can trap and absorb organic chemicals and chlorine from the water effectively with its ability of mechanical filtration and physical adsorption. It can efficiently remove odors and improve the water taste. Carbon Block Filter (Replace twice a year) - Activated Carbon filters can trap and absorb organic chemicals and chlorine from the water effectively with its ability of mechanical filtration and physical adsorption. It can efficiently remove odors and improve the water taste. Post Carbon Filter (Replace once a year) - Activated Carbon filters can trap and absorb organic chemicals and chlorine from the water effectively with its ability of mechanical filtration and physical adsorption. It can efficiently remove odors and improve the water taste. What's in the box 1x sediment filters, 1x granular activated carbon filters, 1x carbon block filters, 1x 75 GPD RO membrane, 1x post-carbon filter