Outdoor folding bag£¬ originated in the invention of the climbers. Mountain climbers in the final camp£¬ the need to hit the peak£¬ it is impossible to carry a heavy and heavy heavy mountain climbing package£¬ so there is such a package£¬ his request is: Ultra light£¬ to maximize the reduction of the weight of the package Two. Collapsible storage£¬ after the folding volume is small£¬ the mountain can be placed in the process of large-scale mountaineering bag£¬ easy to carry. Three.25 liters of capacity£¬ can put down a certain amount of beverages£¬ warm clothing£¬ life-saving appliances. Four. A certain amount of water resistance£¬ the fabric is more robust and tear resistant. Five. Shoulders can be carried£¬ completely free both hands -- so£¬ this type is called the red top pack.