The LST955 from Lision Technology is an NPN Bipolar Junction Transistor. It has a collector-emitter breakdown voltage of 140 V, a base-emitter voltage of 6 V, and a collector-emitter saturation voltage of less than 0.37 V. This transistor has a collector current of 4000 mA and a power dissipation of 1000 mW. It is available in a surface-mount package.