GrandviewTM 12V Horn Wiring Harness Kit For Car Mount Tone Horns(Horn Not Inclueded Do not require modification line, easy to install. After the change , the controller power is only 1.6W,then the original line is very safe. Isolate switch direct electrical contact with the horn, so it does not affect other electrical appliances, let 4S have nothing to say Heavy duty, High efficient, Heat resistant, Never melt; Condition: Brand New Connect up to two horns