Purenex 5 Micron Sediment Filtration 2 Pack Replacement Cartridges 2-Pack of Standard 10" 5 Micron Sediment Filters This is a filter for a standard Reverse Osmosis Water Filtration Unit or any type of Water Filtration Unit with 10" housing Lifetime: Replace two or three times a year, depending on the water quality This filter is wrapped and sealed and meets NSF Standards and Regulations Dimensions: 10" x 2.5"