Using your Avenue R - 50 COB rear bike light is easy. First, make sure it's fully charged. You can check the battery indicator; green means it's good to go. To turn it on, just press the button. It will remember the last mode you used thanks to the memory function. There are different modes like a high - flash mode for high visibility and an economic - flash mode for longer run - time. When riding, especially across traffic lanes, the side illumination ports will help drivers see you better. As for charging, use the USB port. When the battery indicator turns red, it's time to recharge. Keep it away from water as much as possible to ensure its long - term performance. If you notice any issues, contact the customer service.