The Osprey SIRRUS 34 hiking backpack was inspired by the patented AntiGravity™ back system technology. It features a fully adjustable, highly breathable AirSpeedTM back system that combines a unified back system and waist belt design with a highly breathable mesh panel. This ensures comfort even in hot weather and with the backpack fully loaded. If you’re into trekking, you’ll love the Stow-on-the-Go System™, which allows you to easily attach your poles. All you need to do is put one end of your pole through the loop on the backpack and the other through the loop on the shoulder strap. The length of the back system is adjustable so that the backpack fits exactly to your back. The backpack is compatible with a hydration pack. It has a designated space between the back system and the backpack. Side compression straps; 2 large mesh pockets on the sides of the pack; axe loop; removable straps for attaching a camping mat.