The 2N4033 is a NPN silicon planar switching transistor manufactured by Continental Device India Limited (CDIL). It is designed for general purpose amplification and switching applications. The transistor has an isolation voltage of 600V and maximum collector current of 1A. It is a low-cost, low-noise, low-power device, making it a great choice for small-signal switching and amplifier stages. The 2N4033 has a wide range of uses in audio and other applications, making it an extremely versatile device.It has a low noise figure, making it ideal for applications such as low-noise amplifiers, envelope detectors, and oscillators. The 2N4033 also features an ultra-low saturation voltage, making it ideal for use in high-efficiency switching applications. The CDIL 2N4033 is also one of the most popular and reliable devices available on the market today.