An X-shaped bar system keeps it upright and stable, while it is (intentionally) suspended flexibly on the back. Straps are only attached centrally at the top, but are all the wider at the hip belt, triangular contact surface combines mobility in the upper body with stability. The bars in the back bulge slightly into the interior, but the huge, divisible main compartment can easily cope with this, and...

A distinctive trekking backpack with many good details. Robust, sustainably made, but too heavy and "bulky" for alpine use.