The iconic a2 challenger is the hydration king of 2 3 hours off road racing equipped with a 25 litre shape shift hydration bladder which keeps water from sloshing around while its super wide opening makes it easy to add ice and turn inside out for cleaning the pack rides on the revolutionary no more dancing monkey harness which secures the pack on your back without affecting your body movement or performancespecificationsvolume 3l 403l41weight 328g ex bladderno more dancing monkey ha