Design of flow decompression between three-dimensional air sacs. Dispersed stress support points, effective and greatly reduce the sense of load. Anti-gravity decompression shoulder strap air bag multi-contact shoulder. Evenly distributed pressure, decompression breathable, cushioned, massage.3D three-dimensional air bag, the use of multiple convection patent technology, 9 for a group of pressure when the gas between the air bag rapid circulation, produce "anti-gravity" effect, uniform distribution of pressure, pressure relief can reach more than 30%. Free the shoulder enable decompression mode. 3D three-dimensional air bag forms unique supporting force and ventilation, soft support. Reduce the area of contact between shoulder and strap.1.Lycra is soft and delicate Decompression at the same time Stress can be massaged to relax the shoulders. 2.When bearing weight the air bags circulate to each other By gas buffering.It has good damping effect. 3.Shoulder pads are provided on the back. Extended Velcro prevent shoulder pads from moving and slipping. 4.Principle of reflect of reflective materials. One more layer of protection for walking at night.