To answer the raceciever comment, they are only as good as the people using them. Tracks require drivers to buy them and then they say maybe 3 words on it all night. They never say 1 till green (usually not important, but sometimes the flag men doesn't give the signal in time), rarely if ever say where a wreck is or that there even is a caution. And then the other problem is drivers not having them on, having it on the wrong channel, battery dieing, flying off the car, or headphones that short out under seatbelts