Crystal Quest® Washable Pre-filtration Filter. Specially designed for use with any kind of water system with an unusually large amount of sediment that can clog up the water filter. This pre-filter helps remove the sediment, thus enabling your filter to work more efficiently and extend the lifetime of filters. installs between the water filter and the tubing. No tools are necessary for installation. Filter elements are easy to replace. Inside is a fine stainless steel filter and an FDA approved 4 micron filter that is easy to clean out.