The AT411-21 Trigger Module is a thyristor trigger module manufactured by BSR CONTROLS. It is a through-hole technology (THT) component and is part of the company's EZYTrigger™ series. This module is designed to control the trigger current for thyristors, having a maximum current of 12 milliamps (12mA) and a maximum voltage of 2.1 kilovolts (2.1kV). This module is designed to provide a cost-effective solution for triggering thyristors in many control applications.