NTE Electronics 2N4401 Silicon NPN Transistor for General Purpose Amplifier and Switch, 600 mA, 40V (Pack of 5): Amazon.com: Industrial & Scientific
NPN PNP Transistors, Ltvystore Silicon Power Transistor Assortment TO-92 Box Transistors Assorted Kit Set BC327/ BC337/ BC517/ BC547/ BC548/BC549/BC550/BC556/BC557/BC558, Pack of 500: Amazon.com: Industrial & Scientific
200Pcs PNP NPN Transistor Silica Gel Power Transistor Assortment Kit for Student Experiment, Maintenance and Production: Amazon.com: Industrial & Scientific
Bridgold 10pcs MJE3055T MJE3055 NPN Bipolar (BJT) Single Transistor,10 A/60V,is Designed for General Purpose of Amplifier andswitching Applications: Amazon.com: Industrial & Scientific