As a health practictioner I have used the ZHC5 from Sota and other Zappers but this is the best one bar none even better than the new ones (Supper Zapper Deluxe 2004 and 2006). All details are available on the web from toolsforhealth (not my web site and I do not know the people there and I've never purchased from them) This machine is awesome ( how many machines use gold plating on their equipment, the ZHC5 does). However, this machine is not sold any longer as the Canadian govt. was becoming a problem to small manufacturers.