Drinking regularly whilst exercising will keep you fit longer.</br>The Deuter hydration systems enable a constant flow of liquid without interrupting the flow of your sports.</br></br>Product Description</br></br>Drinking regularly whilst exercising will keep you fit longer. The Deuter hydration systems enable a constant flow of liquid without interrupting the flow of your sports.</br><br/>http://www.amazon.com/gp/product/B004PIO28Y