The Replacement 2.5 Liter Bladder is a useful and handy hydration system for a variety of outdoor activities. The aqua-blue colored water pack is rather light and can take as much as 2.5 liters of water which is sufficient to last you for a good amount of time in the outdoors. The water pack also comes with a long hose that can be used to sip water directly out of the pack. This is highly effective and useful for those looking to avoid the hassle of carrying a water bottle around and getting it out of the backpack each time you want to take a sip. The bladder is highly useful for people who are into hiking, mountain climbing, camping and other similar activities where carrying water is absolutely essential.