Board-To-Board connectors are used to connect circuit boards with the need for a connecting cable, and can be used as either a “fit and forget” permanent set up, or as an interchangeable set up that can be adapted or switched as necessary. For a permanent installation, the circuits are connected by the board-to-board connector which is then soldered into its permanent position. The soldering process used for this is known as “hard soldering”, and sees the pin header being soldered to the circuit board at both ends.