A USB Killer is a device that looks similar to a USB thumb drive but instead sends high-voltage power surges into the device it is connected to, which can damage hardware components. Its manufacturers claim the device has been designed to test components for protection from power surges and electrostatic discharge; however, the device is not used for device testing by any major company. The device is often mentioned in articles warning readers against plugging in unknown USB drives.[1][2][3]