During the 1920s and 1930s, several French luxury car manufacturers used three-speed or four-speed preselector gearbox manufactured by Cotal. A unique aspect of the Cotal gearbox was the use of electromagnetic clutches (instead of band brakes) to engage the gears. A downside to this approach was that a loss of electrical power meant that the engine could no longer drive the wheels. The clutches were controlled by a simple dashboard or column-mounted switch, described as "a cherry on a cocktail stick", and relays. There was no mechanical servo action, so no need for the Wilson's cam or toggle arrangements and the change gear pedal.