These eco-friendly tanks are made from a recyclable polypropylene that is a thermoplastic polymer widely used in many different applications due to its rugged and resistant nature, as well as its recyclability. The professional grade, heavy-duty tank material can easily be installed either inside or outside. The tanks will be incorporated into the Products Pro Combo System, which features a four-stage Carbon Series water filter and the cutting-edge DVGW certified NaturSoft salt-free water conditioner.