Tone's blinker has two settings - blink rate and duration of blinking (after which it goes to solid on). I have mine set to the fastest blink rate and the shortest duration which is about 5 seconds with around 6-7 full blinks. First time I went driving with it installed, the lady behind me must have been hypnotized because I've never been tailgated so closely. But, after that it seems to have had the intended effect, especially in abnormal cases like having to stop in the middle of nowhere for road construction and that sort of thing.