The Hyrda-PRO hydration pack is a great way to stay cool on those hot summer rides. The open mesh shoulder straps allow the skin to breath as opposed to suffocate underneath bulky heavy padded straps and the chest strap keeps the pack in place while riding. You will never go thirsty again with the high-flow bite valve and a 2.5L fluid reservoir included in the Hyrda-PRO Pack. With all the features of a more expensive hydration bag the Origin-8 Hyrda-PRO Pack is one of the elite value bags on the market. So get out there, save some money and Origin8 Yourself!