"Amphipod® AirFlow Trail™ Pack: The Amphipod® AirFlow Trail™ Pack is a unisex running waist pack built for trail runners and fitness athletes who need lightweight, hands-free storage without the bounce or bulk of traditional packs. The AirFlow Mesh™ construction keeps your back breathable during longer efforts, so heat and moisture won't build up when you're pushing hard on technical terrain. The ergonomic, ultra-light design stays put in motion, moving with you rather than against you, while the expandable main pouch and external gel slots give you quick access to nutrition, keys, and your phone without breaking stride.The 1.5"" fully adjustable stretch belt accommodates a wide range of body types and dials in for a secure, non-confining fit at any pace. The main pouch measures 10"" x 4.5"" and expands to hold twice its volume when you need extra room, then stows flat when empty. Dual internal compartments with a divider keep your essentials organized, while external nutrition slots let you grab gels on the go. Zippered security keeps your valuables locked in across varied terrain, and the pack fits iPhone® 6, 6 Plus, Galaxy® S6, LG® G3, HTC One M8®, and similarly sized devices.Why Our Fit Experts Love It""I took the AirFlow Trail™ Pack out on a warm weekend trail run and was surprised by how little I noticed it was there. The mesh kept things comfortable against my back, and having the gel slots on the outside meant I never had to stop to dig for nutrition."" - Sawyer, Road Runner Sports Fit Expert, Wilmette ILWho It's Best ForThe Amphipod® AirFlow Trail™ Pack is best for trail runners, hikers, and fitness athletes who want organized storage for a phone, keys, and nutrition without a bouncy or restrictive fit. If you're training on technical terrain or running longer efforts where you need hands-free carry and quick access to fuel, this pack delivers the lightweight organization you need. VIP Family members can take the AirFlow Trail™ Pack for a 90-Day test drive with our Perfect Fit Guarantee."