It's a transistor kits which have 10 Most common types of transistors which can be used in any DIY project. Total Number of Transistors: 30 (10 Types). Quantities are divided among different values on the basis of common requirements such as the most common type: BC547, 2N2222 have more numbers than BD140 and TIP32C. 2N7000 (MOSFET) is also provided. Transistor Kit | Transistor Box | Assortment of 30 transistors | 10 Types | Different Wattage Transistors | Power Transistors.