ST04-18F1-5103 with Zener Diodes Power Zeners Trankillers manufactured by Shindengen is a device that provides voltage regulation and surge protection against transient voltage spikes. It is equipped with an anode, a cathode, and several Zener diodes which work together to regulate and protect against voltage surges. The Zener diodes used are rugged and reliable, allowing the device to handle any standard industrial or commercial voltage. It's also designed to be used in a wide range of situations, such as power supplies, electric motors, and in automotive applications. The ST04-18F1-5103 is approved for safety certification by UL, CSA, and VDE standards.