I have a Back Off modulator for sale. It can be connected to do 2 different modes. Mode #1 This mode emits 3 short brake light flashes and then one long flash and repeats. The signal automatically repeats itself as long as the brake lights are on. This pattern is not random, but has been selected because of its ability to retain following drivers attention Mode #2 This mode emits a visual signal of 5 quick flashes, followed by a steady on light that remains steady as long as the brake lights are on. Easy installation. Instructions included Text or call 250 756-8848