Water Bottle Pocket: External dual pockets feature elasticized mesh, which expands to secure various size water bottles. Airbag and massage,shoulder protection. Aiguillette double high-density air-filled sponges, soft, comfortable, and provided a good shoulder protection. Headset jack in the backpack straps. Unique back design Breathable and padded back design and air mesh backpack straps can be adjusted to provide a more comfortable carry while evenly distributing the weight on your back.