Gregory Arrio 24 Men's Hiking Daypack - Ventilated Trail Pack for Day Hikes & Outdoor Adventures Some backpacks can't wait to get out of the house — and the Gregory Arrio 24 is one of them. Built for hiking, touring, jogging, and everything in between, the Arrio 24 pairs a ventilated FreeSpan mesh backpanel with multiple quick-access pockets and a built-in hydration system for all-day comfort on the trail. Whether you're hitting a local Calgary trail or heading deep into the backcountry, this men's hiking daypack keeps you cool, organized, and ready to move. FreeSpan suspended open-air mesh backpanel creates a ventilated air gap between your back and the pack, keeping you cool and comfortable on warm-weather hikes and high-output trail days Perforated, breathable shoulder harness with integrated hydration hose routing and sternum strap with built-in safety whistle for hands-free hydration and trail safety Internal hydration sleeve with SpeedClip hanger compatible with Gregory's QuickDry 3D Hydro Reservoir for on-the-go trail hydration (reservoir not included) Top-loading main compartment with secure drawstring closure for fast, easy access to layers, gear, and trail essentials Top zippered quick-access pocket for keys, snacks, sunscreen, and small trail items within reach at all times Front vertical zippered stash pocket for a rain jacket, extra layer, or bulkier items Swing-around side zippered stash pocket with key clip attachment for secure, fast-access organization Side stretch mesh pocket sized for water bottles and hydration flasks Removable webbing hipbelt for customizable load transfer and comfort on longer day hikes Front buckle closure with reflective attachment loops for low-light visibility and gear attachment Custom ComfortGrip molded zipper pulls for snag-free, easy operation with gloves on