Generally, when purchasing a built-in backpack, the structural design of the backpack must have the following basic items:
Whether the bottom of the backpack is double-layered, which can increase the durability of the backpack. The extension pocket at the top of the pack must be able to extend upwards and the tight extension pocket must be able to seal. The compression straps on the outside of the pack must shrink the pack and prevent it from shaking. Backpack side pockets must be easily removable.
The backpack must have tow loops and ice axe loops to carry crampons, snowshoes … and other items. Whether the durability of the backpack meets your needs.
The degree of waterproofing of the backpack. In case of zipper failure can continue to use. The backpack must be covered with a waterproof cover, although the backpack has a waterproof treatment, rainwater can still seep through the seams, pocket tops or zipper seams.
After checking the appearance, take the backpack up and face the mirror, pay attention to the following:
The backbone of the backpack must be 2 to 4 inches higher than the shoulders, and the upper bag should not exceed 5 or 6 inches above the shoulders , otherwise reselect a knapsack. The center point of the belt
should be in the center of the ischium when carrying it, the ends of the waist pads should not be too close to each other, and the part without the pad should not rub against the stomach, and do not choose a belt that is too tight. Adjust the fixing point of the shoulder strap, the curve of the shoulder strap must be close to the back of the bearer, the shoulder strap should be about 2 to 3 inches below the top of the shoulder, and the end of the shoulder strap should be grasped with both hands, and the fist must be below the armpit. The head cannot hit the top cover of the pack and cannot hinder the wearing of the helmet. The chest strap must be able to assist the bearer through difficult terrain.