The discussion will now focus on some of the key parameters associated ESD protection devices. The first parameter to be discussed is the reverse standoff voltage VRWM. This parameter specifies the maximum operating voltage on the protected line. VRWM is the breakthrough voltage of the protection diode at which it becomes conductive in the reverse direction, shunting the overvoltage of an ESD strike to ground. The value of VRWM must be greater than or equal to the maximum operating voltage; otherwise the protection diode will become conductive during normal operation and disturb the functioning of the electrical device. However, a small leakage current at operating voltages cannot be prevented; therefore, the maximum leakage current, IRM, at the reverse standoff voltage is defined. The value of the maximum reverse leakage current may of course not exceed the maximum allowed leakage current of the protected application.