Read through the Tello Quick Start Guide before flying.  Compatible remote controllers sold separately. The remote controller shown in the Say Hello to Tello video is a customized GameSir remote controller.  Estimated flight time is based on flying in windless conditions at a constant speed of 9.3 mph (15 kph). Actual flight times may vary depending on your environment.  Attainable when FCC compliant in an interference-free environment.  Propeller guards are recommended when using these functions. Fly with caution.  Failsafe Protection is automatically enabled when mobile device signal is weak or lost, the Tello App crashes, or the aircraft’s vision positioning system fails for more than 3 seconds.