Inspired by Osprey's AntiGravity™ technology, Sirrus 26 provides a fully adjustable AirSpeed™ ventilated back system which combines single piece construction of the backpanel and hipbelt with highly breathable suspended mesh. This allows for increased comfort in warm weather, even with a heavy load. Sirrus' backsystem also offers an impressive women's specific fit, with an ergonomically shaped hipbelt, harness, yoke and backpanel.