I have been using the Universal Colloid Master for over 5 years and it is still working at optimum capacity! It produces wonderful Colloidal Silver waters that all of my friends and family use daily! I am also so thrilled that I got to speak with such a knowledgeable friendly woman when I called in about the additional Colloid Master AC I just purchased. She was happy to answer any questions I had on the process creating Colloidal waters and the generator they created. This generator truly is a wish come true for myself and everyone I share the Colloidal waters with! Thank you so much for all you do!