USB to ESP-01 adapter module has CH340G USB to TTL driver IC onboard, so you can easily use your computer to do ESP-01 functional debugging. ESP-01 serial wifi module can be directly plugged into the yellow pin header without any connection wires.

Features:
Working voltage: 4.5V - 5.5V (On-board 3.3v LDO Regulator)
Working current: 300mA(LDO regulator can supply)
Selectable working mode: On-board toggle switch. UART side for serial TTL debugging by AT commands, PROG for firmware programming
USB to serial TTL chip: CH340G
Logic level: 3.3V
Applications: Home automation, sensor networks, industrial wireless control