The gameport based TSW defaulted to combined gas and brake axes. It requires this switch to enable separate gas and brake functionality (which is more realistic). We still offer this switch if required, though it is probably a good idea to consider upgrading the controller to USB instead.
The switch is easy to install, it simply plugs into the existing wiring and mounts into a hole on the right side where the cables are located. Not all TSW models can use this switch, it requires molex wiring, which can be found on 2nd and 3rd generation TSW controllers.
For TSW Evolution models use the Pedal Mode Switch. For TSW2 models use the single/dual adapter kit.