Deuter Aircontact Lite 40 + 10 Backpack 3340123 Properties: Deuter Aircontact Lite 40 + 10 3340123 is a unique trekking backpack for mountain hiking enthusiasts. Its 40-liter capacity, expandable to 50 liters, provides ample space for all your essentials on long expeditions. Equipped with the advanced Aircontact Lite ventilation system, it ensures wearing comfort even during intense exertion.