Cygolite TridenX 600 LED Li-Ion: Triple LED Bike Light with Stem-Mount Li-Ion Battery Long-lasting LED bike light with 3 high-brightness LED bulbs 4 brightness modes: high, mid high, mid low, and low Fast, slow, walking, and SOS flashing modes for safety Rechargeable battery lasts for up to 12 hours on low setting Heavy-duty flip-lock handlebar bracket and helmet mount