On the top of aluminum bar there is a hard plastic board connected ,which transfer the weight from the top of backpack to the bottom and minimize.

The bottom of valuminum bar is connected to thick waist mat that allows hip move freely during walk;

The side next to body is breathable nylon meshcloth and highly elastic sponge which reduces the losd pressure on the back effcetively;

The knapsack system can go up and down quickly whin a certain scale according to user's height;

There are suitable plastic materials inside of fexible three-layer waist protector,which connected waist protector and coxa closely,not only prevent shaking but also not affect walking.

The fastener uses popular ITW steel engineering plastic fastener,which guarantees all parts to the connected safely and can be used smoothly.