Outdoor backpack buying common sense Generally choose the built-in backpack, first look at the structural design of backpacks, must have the following basic items: The bottom of the backpack is double deck, so that the durability of the backpack can be increased. The extension bag at the top of the backpack must be extended upwards, while the extension pocket must be sealed. The compression belt outside the backpack must be able to shrink the backpack volume and prevent shaking. Backpacks, side bags should be easy to assemble and disassemble. The backpack must have traction ring and ice axe loop provide carry crampons, outdoor shoes... Other items. After checking the appearance, then carry your backpack back to the mirror and pay attention to the following: The skeleton of the backpack must be 2~4 inches above the shoulders, and the upper bag should not exceed 5 or 6 inches of the shoulder, otherwise a backpack shall be re elected. When carrying, the center point of the waistband should be placed in the center of the sciatic bone, and the ends of the waist gasket should not be too close to each other, and the part without shims can not be rubbed against the stomach, and the tight belt should not be chosen. Adjust the shoulder strap fixation point. The curve of the shoulder strap should be attached to the back of the victim's shoulder. The shoulder strap should be about 2~3 inches below the shoulder top, and both hands should grip the end of the shoulder strap. The fist must be below the armpit. The head can not hit the top of the backpack, and can not obstruct the helmet. The chest straps must be able to help the bear survive the difficult terrain How to properly pack backpacks to reduce the carrying capacity To use an umbrella tent attached to a backpack, top fuel oil and water shall be separately placed to avoid contamination of food and clothing, heavy backpack items at the center and lower side band, such as clothing (must use a plastic bag and sealed by different color ribbon so easily recognizable), personal apparatus，headlights, map, compass, camera, attached to a light below items, such as sleeping bags (must be sealed with waterproof bag), camp column can be placed in the bag or backpack backpack in the rear cushion, prepare a long belt tied to some items, such as three tripod, camp column or on the side bag. For male and female backpack is not consistent, because the boys and girls of the upper torso long upper torso is short but long legs, carefully choose the right backpack, loading weight set high when the boys, because boys focus position close to the chest, the girls lower heart location close to the abdomen, weight items to close back, let the weight above the waist. Climbing (climbing backpack) back packing during filling position is close to center of the pelvis, the center of rotation of the body, so as to prevent weight shift to the shoulders, hiking, backpacks filled with high gravity can be close to back. Fuel oil and food must be placed separately, pay attention to the cooker or boiler group loading, do not make the back uncomfortable, pot set in rainy days into the tent, wipe clean. Loading backpacks is not to throw everything into backpacks, but to back comfort and walk happily.