2n2222 Transistor is most commonly used NPN transistor for hobby/school projects. It is available in various package like TO-92 , TO-18 , SOT-23 , and SOT-223. The TO-92 is a widely used style of semiconductor package mainly used for transistors. The case is often made of epoxy or plastic , and offers compact size at a very low cost. 2n2222 Transistor Pinout: It comes with descent collector current(Ic) 600mA and 625mW power dissipation which is suitable for most of applications.The max collector emitter voltage of the transistor is 40V. Download Datasheet: https://www.onsemi.com/pub/Collateral/P2N2222A-D.PDF Applications: 1. As a Switch to drive relay or small DC motors 2. As a Audio Preamplifier 3. RF sensors 4. Sensor circuits 5. Many more...you will find on this site!!