Shelco 4.5" x 10" 1 Micron String Wound Sediment Pre-Filters Three Filters.

Use this Shelco highly effective filter as the first filter before the P4.5-10 NanoCeram ultra filter.  These are gradient density for longer life, string wound sediment pre-filters. There are three layers of filtration, outer layer is 20 micron, second layer is 5 micron and the inner layer is 1 micron. NSF component, shrink wrapped for purity with the micron rating molded into the cartridge.