The leads of these two varistors have been wound around a nickel-coated steel spring ring an then attached to stainless steel ear wires. This is a series of 2 produced. A varistor is an electronic component with a "diode-like" nonlinear current–voltage characteristic. The name is a portmanteau of variable resistor. Varistors are often used to protect circuits against excessive transient voltages by incorporating them into the circuit in such a way that, when triggered, they will shunt the current created by the high voltage away from the sensitive components. A varistor’s function is to conduct significantly increased current when voltage is excessive. They come packaged in a real, translucent gray zippered anti-static bag on anti-static foam, sealed with an "Authentic" tamper-evident holographic sticker.