A combination set of two complete units, one Grand model (our most powerful standard size residential model) and one Duplex model, which treats both cold as well as hot water lines, offering the best in overall protection. The larger unit is designed to work the cold water line and the smaller unit is designed to service the output of your water heater. This is our best-selling overall item due to the complete protection it offers. These units work wonderfully with a salt-based system as well and adds features to your water treatment program that salt systems cannot do alone such as add in pipe build-up reduction and protection to water usage appliances.  We do ship internationally to nearly every country. Any taxes and duties imposed by your country is you responsibility however.