Clear Choice Micron Filter Sleeve. To enhance your filtration system, this fine micron sleeve attaches to your existing pleated filter. Even though you may have more than one filter, it is advisable to cover at least one of them. Does not need to cover the entire spa cartridge filter to work. Easy to clean and maintain. This Micron Filter Sleeve is good for approx. 4 years of use. (spa cartridge filter not included)