AllTrail Hydration Pack 10L A versatile 10L backpack that has you covered from travel to weekends on the trail. Featuring a handy hydration system  and plenty of space for your belongings, you will be reaching for this practical pack every time. 2.5L Patented ReTrakt hydration system 10L capacity and streamlined design A pocket for the essentials Quick-access side pockets Detachable waist strap Comfortable, breathable back panel Interior zip mesh pocket