Because of the 10L cargo storge the 1.5 Hydration MTB Lite is the perfect bag for those long rides where you may need to carry a waterproof coat should the weather change and some tools in case repairs are needed, also includes a 1.5L bladder and bite valve, there is also a magnetic catcher that comes with the feed tube, so it stays in place. We have a new one size fits all harness system for the chest to ensure the bag stays in place and AirLine back ventilation ensures sweat is kept to a minimum. Dual hydration tube routing means you can choose, over the shoulder or under the arm/left or right.