Nu-Calgon Nu-Calgon 4387-02 Vital Flo Tankless Water Heater Descaler $22.61 Nu-Calgon 4387-02 Replacement PartIncludes:(1) - Vital Flo Tankless Water Heater Descaler (4387-02)Specifications8 Fl. Oz. Or 236 mlPhosphoric AcidLength: 6"Diameter: 2-1/16"Replaces Old Nu-Calgon...