Hydration Backpack- Bladder Bag for Cycling Running Hiking with Free 2L Hydration Bladder 2L (2000 ML) bladder with wide opening for easy filling and cleaning. 2L replaceable hydration bladder with a large opening which allows you to add ice cubes to keep your drinks cold. The manufacturer, NEESIX offers a 100% money-back guarantee. You have nothing to lose, if you are not completely satisfied with the backpack, you can return it for a free replacement or a full refund. Click Add to Cart to buy now.