CRE-1 cartridges are manufactured from a sintered ceramic filtration media. They are designed and tested for the reduction of Cryptosporidium and Giardia cysts, and are ideal for fine sediment filtration applications. The fine ceramic media will effectively trap dirt, sediment and cysts down to 1-micron in diameter. A proper fit is ensured, and water bypass is prevented, through the use of a knife-edge seal.CRE-1 cartridges are easily cleaned with water and a damp cloth, sponge or stiff nylon brush. They can be cleaned  several times until the diameter at the smallest point is 1-1/2" or the circumference is 4-3/4", extending cartridge life.