This is a Molex Picoblade cable used to connect a Black Magic Probe to a Lisa/S or Lisa/M(X) autopilot.
The Black Magic Probe provides an auxilary TTL level serial interface connector. This connector is a Molex Picoblade 4 pin header. The pinout (Left to Right) is:
The Lisa/S Serial Interface Adapter as well as the Lisa/M telemetry and GPS serial connectors have the following pinout:
The serial cable connects the Black Magic Probe to an Autopilot. As both sides of the serial cable use the power pin as an output to provide power to a peripheral, this cable is not connecting the power pins together. The appropriate sides of the wire are designated with a shrink tube label: