The Avalon 2 Stage replacement water filters are suitable for Avalon Bottle-less Water Coolers manufactured after April 1, 2018. It consists of 2 filters. An NSF certified activated carbon filter (listed as model Avalon A4FILTER) which will eliminate chlorine, lead, rust, bacteria, or any harmful or unwanted minerals from the tap water that flows through it. As well as a sediment filter (listed as model Avalon A5FILTER) to filter out any rust or large particles of dirt in the water. The filters can be easily replaced into the cabinet of the water cooler. The filters have a capacity of 1,500 gallons of water and is made to last for 6 months of use. They have a flow rate of 0.5 gallons per minute. Both filters must be used together. Your water will be tasting crisp and pure with these installed in your water cooler.