< 7 PACK RO Filter Premier 1-Year 5-Stage Reverse Osmosis Replacement Filter Kit Made by: Unit Price: $29.99 The specifications of the set are as follows: 2 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: 5 Micron. Dimensions: 10" x 2.5" 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. Filter will fit any Residential Reverse Osmosis Unit that features standard 10” filter housing 4 of Block Activated Carbon filters – Block Carbon Filters are similar in their performance to that of GAC filters, being made of fine coconut shell carbon they also do remove odors and tastes of many organic compounds, chlorine especially. Though, because this filters are made of a packed carbon (forming a cylinder block), they offer a much finer filtration of suspended particles and dirt. Micron rating: 5 Micron. Dimensions: 9.875" x 2.5" 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. Filter will fit any Residential Reverse Osmosis Unit that features standard 10” filter housing 1 of Inline Granular Carbon Filter is also known as polishing filters, because they would usually be the last stage of any standard Reverse Osmosis circuit. Being made of high quality coconut shell carbon they stabilize the water tasting qualities and further remove any traces of bad tastes and odors. Dimensions: 10 " x 2" Lifetime: Replace ones in 2 years. This filter is wrapped and sealed and meets NSF Standards and Regulations.