2BN4A is a small signal NPN BDX-34 transistor manufatured by Raytheon. It is commonly used for amplification and switching applications. It has three leads, an emitter, a base, and a collector. The maximum collector current is 40mA, the maximum collector-emitter voltage is 30V and the maximum collector-base voltage is 40V. The maximum power dissipation is 230mW and the hFE is 700.