Sino-Microelectronics Co., LtdThe 3DD13005ED-126S is an NPN transistor manufactured by Jilin Sino-Microelectronics Co., Ltd. It has a power rating of 400 Voltage (V) and 4 Amps (A), and is packaged in a TO-126S form factor which complies with RoHS standards. It is an NPN type transistor, meaning that it has a collector, an emitter, and a base. NPN transistors are known as current-controlled devices: when the base current increases, the collector current increases in turn, allowing the user to control larger currents. The 3DD13005ED-126S makes for a great choice when high power outputs are needed, as it can handle up to 400V and 4A.