2N2222A by Texas Instruments is a small signal NPN bipolar junction transistor (BJT) with a max collector-emitter voltage of 40V and a max collector current of 0.8A. It is commonly used for switching applications due to its fast turn on/off times (35ns/285ns) and high transition frequency (300MHz).
N-CHANNEL; Configuration: SINGLE WITH BUILT-IN DIODE; Surface Mount: YES; Maximum Power Dissipation (Abs): .36 W; Package Shape: RECTANGULAR; Terminal Finish: Matte Tin (Sn) - annealed;