Well I use an OFNA brand one, all you do is connect it between your throttle servo and your reciever. Plug your throttle servo into the failsafe, and plug your failsafe into the reciever. Now, turn on your transmitter then turn on your car. Next, hold the program button on the failsafe until it starts to blink, while holding the button, apply full brake, tthe failsafe will start to blink after about 5 to 10 sec. then release the brake. It should be programmed. Just follow the instructions that comes with the failsafe. To test it, turn on both your transmitter and you car, then turn off you transmitter, your throttle servo should go to full brake, if not, check your programming instructions and reprogram.