ATTENTION ALL BACKPACKERS! VENTILATED 3D PADDING SYSTEM FOR UNRIVALLED BACKPACK COMFORT The AirDuct™ Pads on the shoulder and hips spread the pressure of the backpack. At the same time, the special 3D weave technology ensures that the sweat-intensive areas under the shoulder and hip belts are ventilated. While you rest, the AirDuct™ Pads act as air chambers and insulation.