<b>Why is this best choice for outdoor sports?</b> <p>High quality water bag</p> <p>Insulated water bag tube</p> <p>Thermal insulation</p> <p>Multi-space multi-layer pocket</p> <p>Adjustable shoulder straps, chest straps and belts ensure that fits your body size</p> <p>Breathable back lining</p> <p>Emergency whistle in case of emergency</p> <p>Reflective strips keep your visibility</p> <p>External rubber bands can be used for extra carrying of other things</p> <p>The keychain ensures that the key is in a clear position</p> <p>Mouthpiece valve is not easy to leak</p> <p>Presumably all of the things here are the focus of every outdoor hobby</p> <p>You have it, it won't let you down.</p>