BUY B631K https://www.utsource.net/itm/p/8853618.html

The B631K is a NPN silicon transistor manufactured by KEC. It is a TO-126 package type and has a maximum collector current of 0.5A. It is designed for general purpose switching and amplifier applications. It has a maximum collector-emitter voltage of 30V and a maximum collector-base voltage of 40V. It has a maximum power dissipation of 500mW. (For reference only)