Caribee Op's Backpack - 50LOften referred to as a 72hr backpack, the Caribee Op's pack is based on a military design that's used for operations up to 72 hours in duration. This 50L backpack has great capacity and full of useful features making it a popular all round choice for outdoor adventures. Brand: Caribee Large capacity 50L operations style backpack Bio form air mesh harness system with internal aluminium stay for extra support Sternum strap for improved harness stability