The advanced Velineon VXL-4s ESC pours on the power you demand for over-the-top fun. An integrated fan cools the oversized heatsink to keep ESC temperatures down and extend run times. Bright LED status lights keep you informed with temperature and voltage warnings. Internal safety programming constantly monitors ESC performance to protect it from damage. The VXL-4s comes pre-programmed with real-time telemetry capability using the optional 6511 Wireless Module (sold separately) installed in a Traxxas TQi transmitter. Use the free Traxxas Link App to see speed, RPM, voltage and ESC temperature directly on your mobile device.