This backpack is equipped with reflective strips and LED lights that will respond to the signal received from the remote control, reminding passengers and drivers to stay away from you. Built-in 500 mAh rechargeable battery. It can work 12-15 hours continuous work after 2.5 hours fully charged. Absolutely a perfect complement for night safety cycling. Features: LED signals, reminding passengers and drivers to keep a safe distance. Wireless control, handlebar mounting, free your hands, safe and convenient. Built-in 500mAh rechargeable lithium battery, easy to charge from your computer or any device with USB port. 12-15 hours continuous working after 2.5 hours fully charged. Ultra light and ultra thin, easy to carry without adding extra burden. Straps adjustable shoulders and waist to fit your body perfectly. Perfect choice for running, cycling, mountaineering, hiking, fishing, cross-country skiing and others outdoor activities.