The BD139 is a BJT NPN transistor from Changjing Electronics Technology which is packaged in a TO-126 case. The type is PNP and the features of this device are wide current capability, high breakdown voltage capability, low cut-off current, and high switching speed. It is RoHS compliant, making it ideal for use in a wide range of applications. The BD139 is designed and manufactured with a great degree of accuracy and reliability, making it a cost-effective device for many operations. With its high-quality technology and design, the BD139 is a great product for many modern consumer, automotive, industrial, and medical applications.