Hyperlite Mountain Gear Southwest 40L - is an ultralight, durable backpack designed for hikers who venture off-trail, where rough terrain demands more protection and gear often takes a beating. Built on the proven Windrider and Junction platforms, it offers the same minimalist performance—now with reinforced materials and fully solid external pockets to better shield your gear.

The pack is now made from NEW Dyneema® Woven Composite 3.9, a fully woven 200-denier fabric that improves abrasion resistance while staying incredibly light and 100% waterproof. Whether you’re pushing through brush, scrambling over rock, or navigating tight forest, this fabric is built to last.

The Southwest 40L features three solid external pockets made from Dyneema® Hardline fabric — perfect for storing gear you want protected from snags, thorns, or sharp rock. Updated pocket shapes and taller side walls make it easier to grab bottles or stash quick-access gear. Redesigned shoulder straps and a sewn-through back panel improve comfort, stability, and load transfer.

Inside, the main compartment offers 40 liters of storage, supported by a roll-top closure that helps adjust volume as needed. A simple internal hydration sleeve and large hip belt pockets keep essentials close, while removable aluminum stays and a supportive foam back panel help distribute up to 18 kg of gear comfortably.

With a starting weight of just 841 grams (size M), the Southwest 40L is a rugged and highly efficient pack built for backpackers who need reliability in tough, remote environments — without giving up the benefits of ultralight design.