This useful cable connects to the Raspberry Pi GPIO (general purpose input/output) 26 pin header.
You can then connect this to your own PCB, stripboard, project etc. Pin #1 is marked with the red wire.
NOTE: We Make these cables up with the strain relief clip attached to the IDC connectors. This makes the connector too high if the Raspberry Pi is to be housed in a case. The strain relief clip will need to be removed if used with a case.