Product Description This is a 50 filters set for a standard Reverse Osmosis Water Filtration Unit or any type of Water Filtration Unit with 10? housing. The specifications of the set are as follows: 50 of Melt-blown Polypropylene Sediment filters ? Sediment filter is often the first filter installed in the Reverse Osmosis circuit. Sediment filters are made of fine melted polypropylene, which is then blown and spun in a cylinder-like form. The main function of a sediment filter is to remove large and fine particles from a drinking water, such as sand, dirt, silt, and rust particles. Removal of such particles allows for a better performance of all the following filters, such as Carbon Block or GAC filters. Micron rating: 1 Micron. Dimensions: 9.75? x 2.5? Lifetime: Replace two or three times a year, depending on the water quality.