Redox potential is measured in volts (V), or millivolts (mV). The usual units are volts (V) or millivolts (mV). A small voltage (around two millivolts per junction) can induce frequencies in the terahertz range. The voltage is usually around 1 to 9 millivolts. Anything beyond a few millivolts is significant, and potentials of 200 mV are common. The resting potential for potassium-sodium channels in a neuron is about -65 millivolts. Other electrodes can vary by 70 to 100 millivolts. Typically, the value of "V" is on the order of a few hundred millivolts.