ULTRA-PRO EVO: pressure vessels with replaceable membranes and an innovative Tecnoprene flange.  Thanks to a tight collaboration with the University of Padua, always ahead in research and development of new materials, a new series of tanks called ULTRA-PRO EVO (Evolution) was born.  The result of this collaboration is this original Zilmet patented flange made of Tecnoprene, a Tecnopolymer with high performance and technical characteristics, that give the tank great mechanical robustness and stability,  resistance to temperature variations and corrosion. These are available from 24 to 100 liters  (5.3 to 22 UK gallons)