Bicycle Travel Backpack Black Air exchange carried system can more effectively attached to the spine and back to disperse the heat when sport to ensure your back ventilation and dry Safe and convenient to use. the reflective strap can be seen by others even travel at night. Survival whistle design when in danger User-friendly design, the water pipe outlet on both sides if the strap design can drink no need stop. external Helmet bag design the backpack thickening sponge protection can effectively reduce the burden hold many stuff, inner compartment can hold water bag, the outer compartment can hold some digital products