The ST20-27F2-5103 with Zener Diodes Power Zeners Trankillers manufactured by Shindengen is a power component used in amplifier, switching regulator, and DC-DC converter circuits. It is a 3 terminal device that is equipped with two Zener diodes. Its chief purpose is to provide a stable voltage reference and to provide over voltage protection. The component offers superior reverse surge characteristics and a high DC breakdown voltage. It is highly resistant to thermal shock and humidity, making it an ideal component for both commercial and industrial applications.