This backpack is made with reflective fabric to increase nighttime visibility and safety. The main pocket has a separate pocket designed for your water bladder to keep you hydrated. The straps are adjustable to make you comfortable. This backpack is great for cycling, camping, hiking, mountaineering, running, and other outdoor activities. Specifications: Material: Reflective fabric Color: Black / Grey (optional) Size: 21 * 9 * 40cm / 8.3 * 3.5 * 15.7in Weight: 320g / 11.3oz Package List: 1 * Cycling Backpack