This unit is a breakthrough in modern alternative therapy. Actually, it is a 3in1 unit, because it combines the therapies of three of the worlds most renknown health practitioners, Dr. Clark, Dr. Beck and Dr. Rife in one unit. Besides having the standard frequency from Dr. Clark, it can also do Zappication (1kHz). Also, the user can chose between the usual 7-20 minutes cycle, as well as 2 hours of continuous zapping. After the program is over, the unit shuts itself off. Therfore,zapping while sleeping is easily possible and safe.