This trekking model is designed specifically for light users. As a new choice for air conditioner tacts, we use a completely new rear system to rereview the materials and parts without compromising the comfort of your back. The long hike with carefully selected gears, the simple and lightweight gear is perfect for mountain climbing. The back length is 3 adjustable levels in 2cm increments, and the fabric is woven with high strength polyethylene fibers for lightweight and durability.