What Our Gearhead(R) Experts Are Saying:"The AirSpeed back panel makes a difference on warm days, because there's enough airflow that my back stays dry even on sustained climbs. The dual front-panel zip gives me full access to the main compartment without digging, which I use more than I expected."Why We Like ItThe Sirrus 24 is built from 100% recycled nylon and a PFAS-free DWR on both the pack and the included raincover. The AirSpeed suspension uses a LightWire perimeter frame to tension a mesh back panel, creating a gap between the pack and the wearer's back for airflow on warm days. The torso length adjusts across 4 inches via an injection-molded ladder system, and the hipbelt uses a seamless construction to eliminate pressure points on longer carries.