Flowmatic Systems Inc. GAC10N KDF Flow-Pur Replacement GAC/KDF RV water filter cartridge is for the Flow-Pur ultimate system. The filter is long lasting, inhibits bacteria growth, reduces chlorine, taste/odor, & voc's. The cartridge interchanges with other brand #5 cartridges. The flow rate is 2.5 GPM. It is NSF Certified.