Features: Multi Pockets: 12 pockets in total, main compartment for 3L hydration bladder and emergency blanket, side pouch for phone, keys, medicine pills, energy bars, and 2 pocket on shoulder strap for soft water bottle. Breathable Lightweight: Water repellent nylon pack with mesh shoulder strap and ergonomic design, lightweight, breathable and comfortable fit on your back. Adjustable Convenient: Quick release buckles in chest for easy on/off and ensure the vest in place during sports, and you can adjust the strap for proper tightness. Extra Bladder: Food grade material, BPA-free, anti-bacteria and thick enough to be pressure-tolerant and wear-proof, and the bladder with a detachable drinking tube for convenient hydrationduring sports. Designed for Sports: 3L water bladder, a hydration vest, an emergency blanket and a whistle, great suit for outdoor running, thru-hike, marathon and exploration.