The Arc'teryx Aerios 18 backpack shows how a lightweight hiking pack can still feel considered. The patent‑pending two-point harness adjustment system lets you dial in the fit before you even hit the trail — no faff, no mid‑hike adjustments. The grid fabric is ultralight, tough, and shrugs off light rain. A hydration port makes it easy to thread your tube outside the main compartment, and the pack’s set‑up is fully compatible for a reservoir bladder (not included). Body: 93. 6% Cordura Nylon, 6. 4% Polyacrylate Lining: 100% Polyester Mesh Durable Water Repellent Finish Adjustable Sternum Strap Removable Waist Belt Bungee Compression System Two-point Harness Adjustment System 2 Trekking Pole Attachment Points Zip Pockets At Shoulder Harness Hydration Port Compatible With Reservoir Bladder Style Code: X000010704-002291 | Arc'teryx Aerios 18 Backpack in Black | Polyester/Nylon/Mesh | END Clothing Color: black