OMNIFilter RS2-DS3-S06 RS2-DS12-05 Standard Cartridge, White Whole house replacement string wound cartridge made from durable polypropylene string Designed for fine sediment filtration for the whole house Reduces sediment, sand, dirt and rust particles to 5 microns Can be used on chlorinated or non-chlorinated water Fits OMNIFilter OB1, OB5, U25, U30 whole house filter housings and other major brands like 3M, American Plumber, Aqua Pure, Culligan, Cuno, DuPont, GE, Pentek, Watts, Whirlpool and others