Descaler Appliance Water Softening Polyphosphate FilterProduct Name: Descaler Appliance Water Softening Polyphosphate Filter Usage: This can be used on the pipe prior to a home appliance water heater, water boiler, ice makers, coffee machinces etc to protect the pipe appliance from scale build up. Description: Protect home appliances from scale build up, corrosion and stops rust and dust particle build up. This 5 inch housing contains a refillable filter cartridge inside which can be emptied and refilled.