BREATHABLE/RUGGED DESIGN: Designed and engineered for runners by runners – the patented AirFlow Trail Pack features a rugged moisture-resistant nylon outer construction and 3D mesh back panel that is breathable and non-chafing, expandable zippered main storage compartment with internal dividers, three gel pack storage slots, and a fully adjustable bounce-free stretch-comfort waist belt. Ideal for running, jogging, hiking, endurance training, trekking, and walking. EXPANDABLE STORAGE: Easy access quick-zip security main storage compartment with moisture protective properties holds phone, ID, cash, credit cards, and keys; equipped with two internal compartments. Storage: 10"x 4.5", weight 4.3 ounces. BREATHABLE: 3D mesh technology wicks moisture away from the body and circulates air between the body and pack for a cool, and comfortable waist carry eliminating sweaty hot spots. COMFORT FIT: Breathable, non-confining, super-slender and fully adjustable stretch-comfort waist belt secures fanny pack comfortably, offering distraction-free essential storage for jogging, gym workouts or any run. Belt width: 1.5”. QUICK RELEASE: Easy on/off with low-profile, quick-release buckle.