Water circulates in and out to cool the motor Low battery alarm - When the battery in the boat runs down, the controller beeps Self-righting capsize recovery feature Trim buttons for throttle and steering Rechargeable battery can be removed and replaced Propeller safety protection - The prop won't spin unless the boat is in the water 2.4 GHz communication technology, transmitter distance is 150 meters, different transmitters use different frequencies so boats can race as a team Out of range warning and signal weakened alarm, when the 2.4 GHz signal weakened, then the transmitter power indicator will start flashing