The MPSW42 is a one watt high voltage transistor that is designed for general purpose amplifier applications. It is a high voltage NPN bipolar transistor that is housed in a TO-92 package. The MPSW42 has a voltage of 300V, a current of 500mA, and a frequency of 50MHz. It also has a maximum power dissipation of 2.5W and a minimum hFE of 40.