The Osprey SIRRUS 36 II hiking backpack was inspired by the patented AntiGravity™ back system technology. It is specially designed for women, it is fully adjustable, features highly breathable back system in combination with unique back system construction and waist strap with highly breathable mesh. This ensures great level of comfort even in hot weather and with the backpack fully loaded. The main compartment with a zip pocket can be accessed through a lid opening with draw-cord fastening. Under the lid, you will find a mesh zip pocket with a key clip. More openings are in the lower part of the backpack and on its side. The backpacks many pockets include a big zip pocket in the centre and two side pockets with a zip for snacks and smaller items. If you’re going trekking, you’ll also love the Stow-on-the-Go System™, which allows you to easily attach your poles. Inside the backpack, you will find a detachable divider for better organisation of your belongings. The Sirrus 36 II is water bladder compatible.