Contains diodes which allow body's natural electrical potential current to flow only in one direction ( from - to +)

Palm-size, 2.3"x4"x1", dual channel unit contains diodes which allow the body's natural electrical potential current to flow only in one direction (from - to +). May be used with any standard 3.5 mm jack alligator clip wires. Insert 3.5 mm jack into CHI and/or CH2. Setting A results in a - black and + red clip. Setting B results in a + black and - red clip. The - clip is generally connected to the area of excess or negative polarity. No battery required.