I won't use flashing lights at night. I believe the lower intensity flashing mode is more then enough for viability at night. Once I have my grandson trained enough for neighborhood rides we will only have a flasher running on the trailing bicycle. I just finished the first charge on the 450Viz and it is quite hyper on the flashing pattern. My Grandsons new bicycle should arrive today. The family wants me to wait for his birthday October 2 but I am to excited to wait that long. If there is a picture of a bicycle on the box : I can accidentally have it viable to him.