With the regular stress of removal and tightening, filter housings and fittings will weaken over time. To prevent unwanted system failure, the filter housings on your systems need to be replaced EVERY 5 YEARS. This kit includes three 10" white filter housings, two 1/4" hex nipples, and two 1/4" MPT x 1/4" quick connect elbows. These housings will fit all standard 2.5" x 10" filter cartridges commonly used on point-of-use RO systems, drinking water systems, and prefilters for ice machines and other water appliances and devices.