Yes it is. It uses 2 electrodes in distilled water making mostly ionic silver. It is a well known Colloidal Silver generator with up to 20 ppm. I use a Silver Puppy that is similiar.
Most believe ppm is not as important as particle size. The smaller the better (more surface area). If you go above 20 ppm conglomeration occurs (particles stick together). I don't see any advantage in condensing into 500 ppm. I think it would be better to just drink more of the 20 ppm instead of drinking larger particle 500 ppm. Maybe our friend knows something I don't.