The 2.5 x 10" carbon pre-filter is the correct replacement filter for all of the Tucker® systems. These carbon block filters are made using 100% coconut shell carbon, a renewable and ecologically sustainable material. -5 Micron nominal filtration -Exceptionally low pressure drop -High dirt holding capacity -Extremely economical These will treat for chlorine only. This product will not help you with chloramines in your water supply. Our item number 20026-CK is superior to this and will work on both chlorine and chloramines.