The MERCYDA Prestige 811 is an electronic road speed limiter that is designed for modern vehicles that are equipped with drive by wire throttle pedal system. The device is installed between the original ECU and the electronic throttle pedal, along with speed sensor and +12v key on supply. To implement the speed control function, the device adjust the throttle request sent from the pedal to OEM ECU to ensure the vehicle speed is limited. Almost all throttle pedal units available today have dual sensing circuits to enhance safety; the SLD also independently controls these circuits, called channel 1 and channel 2. The SLD also has built-in tampering modes enabled.