Michael Josh Hydration Pack Backpack with 2 Bladder,Lightweight Water Reservoir Bag Backpack for Cycling Mountain MTB Bike Hiking Camping Lightweight comfortable design,adjustable shoulder and waist strap fit your body perfectly,airflow system keep your back cool and dry 12L large volume let you have enough space to storage daily necessities, clothes,smaller than 13" laptop BPA free 2L water bladder bag,large opening desgin,easy to clean,easy to drink With unique helmet net ,best for outdoor cycling MTB mountain bike sports 4 zippered side pockets design,extra space to storage your wallet cellphones