1.Large capacity,light weight: Internal size(40CM*25CM*5CM),0.32KG,lightweight and practical,in total 6 pockets,including three large pockets in front, one anti-theft pocket on the back,three on the front Pocket:Large pocket size (35*25*4CM),medium size pocket size (25*20CM),small size pocket size(20*20CM).The pocket size on the back (30*25CM).The small pocket on the strap hold a variety of small cards.water bottle pockets on the right side,place paper,etc. 2.Usage occasions: Suitable for left-handed products. The design has a tempered D-shaped plastic buckle on both sides of the bottom of the back of the product. It is matched with the tempered G-shaped plastic buckle on the strap. It is hard and durable. When used, it can be backed up. The chest on the left can also be on the right side, and can also be used as a backpack on the left and right back. Can meet outdoor sports, running, climbing, going to work, short trips, learning and more. 3.Practicality of the product: The nylon fabric of the product is made of 230D encrypted polyester. The material is light, the material is resistant to tearing, no fading, environmental protection, comfortable hand, odorless, etc.; the zipper head is made of zinc alloy, not for 3 years. Will rust, strong use, encrypted thick zipper, has passed 50,000 pull test; webbing thickness of 1.2MM, can easily bear 10KG. Reflective strips, night sports, can avoid being hurt, eyes can be placed on it. On the 4.Heat Dissipation: The backside of the product is a heat-dissipating material design. The design of the venting holes and heat-dissipating materials on the straps does not cause heat to the parts of the body, and has better ventilation and ventilation effects.