The MCR708A1G is a four-amp, 600-volt silicon-controlled rectifier (SCR) made by the manufacturer Littelfuse. An SCR is a unidirectional, three-terminal semiconductor device that can control high-power application when bypassing current in one direction. This specific SCR is designed to be used in motor control, lighting dimmers, AC inverters and tools, and other high-power applications. It features a 3500 V peak off-state voltage and is made of robust materials, making it able to withstand corrosive atmospheres. This SCR is available in TO-220F, non-invasive, and faston packages.