Omnipure CSM5621 Carbon Block Filter - Water Factory 3M CompatibleThe Omnipure CSM5621 is a replacement 5 Micron Carbon Block Filter designed to be compatible with 3M manufactured SQC filters for Water Factory CUNO (now 3M) and for older Ionics Reverse Osmosis systems. The CSM5621 carbon block filter improves taste and odor, reduces chlorine in your water, and reduces sediment particles up to 5 microns. The CSM5621 is a replacement for the 47 9298G2. In 3 stage systems its often used as a post filter and in 4 stage