This 15L waterproof backpack is equipped with reflective strips and LED lights which will respond to signal received from remote controller, reminding passengers and drivers keep distance from you. Built-in 500mAh rechargeable battery. It can work 12 -15 hours of continuous work after 3 hours full charging. Absolutely a perfect add-on for night safety cycling. Features: 4 Led signals, reminding passengers and drivers to keep a safe distance. Wireless control, mounting it on handle bar, free your hands, safe and convenient. Waterproof and rip stop nylon material makes you ride daringly in the raining. Built-in 500mAh rechargeable lithium battery, easy to recharges from your computer or any device with USB port. Adjustable straps to fit your backpack perfectly. Perfect choice for running, cycling, mountaineering, hiking, fishing, cross-country and other outdoor activities. Specifications: Material: Nylon + PC + ABS Color: Black Working Time: 12 - 15h Charging Time: 3 hours Battery: 4.2V, 500mAh Bag Size: 40 * 25 * 15 cm / 15.7 * 9.8 * 5.9 in Bag Weight: 260 g / 9.2 oz Package List: 1* Bag 1 * Wireless Controller 1 * Controller Mounting Base 1 * USB Cable 4 * Zip Ties 1 * Manual