WX3in1 Plus 2.0 serial interface cable. It allow you to connect WS-23XX family of weather stations on serial port 1 and GPS receiver on port 2.
WS-23XX weather stations require a bit exotic connection method. There is no GND connection and both positive and negative 5V voltages are necessary for interfacing. To connect WS-23XX weather station, we need to use PORT2 TXD as negative polarization voltage source.
Cable schematic: download