Everpure Kleensteam II Twin Water Filter System EV979722Application: Steam This is the larger version of the Kleensteam II Single system, part # EV9797 21. This larger system has double the filtration capacity with two water filter cartridges instead of one. Here is a link to the replacement water filter cartridges for this system. Specs: Capacity: Alkalinity Range: 2 to 12 grains per gallon Maximum Flow: 5. 0 gallons per minute twin cartridges Micron Rating: 5 microns Certification: NSF Standard 42