Jack wolfskin stratos 20l rucksack the jack wolfskin stratos 20l rucksack is designed for hiking cycling and mountain bike trips it has a main zipped compartment front zip pocket with internal pouches smaller lined zip pocket for glasses or a media device two open side pockets internal hydration system compression straps reflective details adjustable padded shoulder straps carry handle rain cover 20 litre capacity and air control system which keeps the back of the rucksack away fro