This cartridge powers the NuvoH2O Water Heater System. The NuvoH2O Water Heater System not only prevents hard water build-up but it reduces and removes existing scale, helping to restore your water heater to near-new efficiencies. The NuvoH2O Water Heater System not only saves on the operating costs of your water heater but can reduce maintenance costs and extend the life of this critical appliance.