The PL2303HX is a USB to UART TTL (Transistor-Transistor Logic) converter module that allows communication between a computer or other USB-equipped device and a UART device through a USB port.
This STP80PF55 P-Channel 55V - 0.016Ω - 80A P-Channel Power MOSFET - TO-220. This Power MOSFET is the least development of STMicroelectronics unique “Single feature size™” strip-based process.