A surge protector is a device that is connected to a system to protect it against overvoltage. It is a component of an electrical protection system used to safeguard equipment in power distribution and transmission networks. These devices protect communications components against voltage transients. Surge Protective Devices (SPDs) are devices that protect a system against voltage spikes. It is a catch-all term for any device meant to guard against overvoltage. Surge protection devices (SPDs) are electrical devices that are often used to guard against electrical surges and spikes, notably those caused by lightning, in-process communications systems, control systems, power distribution panels, and other heavy-duty industrial systems. Only at Renown System can you get the highest quality Surge protection Device at affordable prices. Contact Us.