There are many manuals where user must not connect serial interface positive voltage wire with target device UART due to risk of short circuit, but only RX, TX and GND. With this serial interface user connects all 4 wires to target device UART without any risk as long as the target device's voltage is between 3 and 5.5 volts. Useful for many ARM boards.

PCB comes with JST PH connector (2 mm pitch) and 20 cm fanout cable. Connector's pin description are written on the silkscreen on the other side of the PCB. Interface supports usual baudrates up to 115.2 kbps and it's supported in Windows 10 and newer and works under Linux.