NTE Electronics NTE3042 Optoisolator with NPN Transistor Output, 6 Lead DIP Type Package, 3V, 3 Amp: Transistors: Amazon.com: Industrial & Scientific
Amazon.com: Major Brands MPSA14 NPN Silicon Transistor, 30V, Through Hole Mount, 5.33 mm H x 4.19 mm W x 5.2 mm L (Pack of 20) : Industrial & Scientific
Transistor Assortment, Npn Transistor Transistors Assortment Kit for Industry for Plug Transistor for PNP Transistor for 2n3904 Npn Transistor: Amazon.com: Industrial & Scientific