The NTE5501 is a Stud thyristor manufactured by NTE that is designed for use in circuits that require a high-speed switching operation due to its fast switching speed and low on-state voltage drop. It has a maximum rated voltage of 50V, a maximum rated current of 16A, and a minimum holding current of 30mA. It comes in a TO48 package, allowing for it to be mounted on a printed circuit board.