+ 12
Weight
842 g
Hyperlite Mountain Gear Southwest 40 (2025)
The new improved version of the popular Hyperlite Mountain Gear Southwest 40 backpack for 2025 is here. This pack, which has won the hearts of long-distance hikers around the world, comes with updated materials and several design tweaks. Because of this, it's even more durable, comfortable, and functional – ready for your next adventure, even in the harshest weather conditions.
Who is this product suitable for?
New improved version of a durable backpack for ultralight and thru-hiking fans.
Durable backpack for trekking
The Southwest backpack is one of the toughest packs from Hyperlite Mountain Gear. Both side pockets and the large front pocket are made from durable material to withstand even the harshest conditions. This backpack is perfect for treks and mountain crossings characterized by dry environments, rocky and stony surfaces, and overgrown trails with dense vegetation.
The 40-liter volume is ideal for shorter and weekend hikes. Thanks to the roll-top closure and compression straps on each side, you can easily reduce the backpack’s size, making it useful even for day-long mountain climbs. If you're thinking of using the Southwest 40 for longer trips, you really need to have a well-tuned and lightweight gear list and the ability to regularly (every 2–4 days) resupply your food along the way.
Backpacks from Hyperlite Mountain Gear are among the most popular on long-distance hikes in America like the Pacific Crest Trail and Continental Divide Trail, and we think that says something (this info comes from annual surveys on the blog halfwayanywhere.com).
Previous vs. new version
In 2025, the backpacks from HMG (Junction, Southwest, and Windrider) are coming with a few significant changes, based on thousands of kilometers of experience in the field:
- Change of material – new Dyneema Woven Composite 3.9 with higher abrasion resistance at almost the same weight, nicer to the touch.
- Improved construction – the sewn back panel creates an ergonomic curve and enhances ventilation; the shoulder straps have a greater curve around the neck for more comfortable wear.
- Pockets - deeper side pockets with a lowered back edge for easier access to your bottle; shortened elastic along the top edge of the side pockets and the large front pocket for a more secure grip on your gear.
- More adjustment options – expanded neck strap adjustment, easier and repositionable compression straps, modified ice axe attachment.
- More changes – simplified hydration (internal hanging loop, port now at the top of the back, without the internal "sleeve"); inside, there are two loops for an optional zip pocket; minor cosmetic tweaks (smaller logo, new pulls, etc.).
Specifications
- Top closure – roll-top system with Velcro, top Y-compression strap.
- Back panel – integrated foam panel (0,6 cm) and sewn-through construction for ergonomic curvature.
- Reinforcement – two removable aluminum stays for better load transfer.
- Hip belt – padded with double-layer foam and spacer mesh, two pockets with waterproof YKK zippers.
- External pockets – two deep side pockets and a large front pocket made of durable Hardline material with Dyneema® and an elastic rim.
- Shoulder straps – comfy, wide enough, and padded shoulder straps with ergonomic curvature.
- Chest strap – sliding and adjustable, with expanded attachment options.
- Compression straps – detachable, variable attachment, with the option to centralize the load.
- Hydration – a simple system with a hanging loop and a port at the top of your back.
- Taped seams – all side seams and the seams under the pockets are taped for increased waterproofness.
- Accessory options – compatible, for example, with Shoulder Pocket, Bottle Pocket, Versa, Pods, inside the loop for attaching an additional pocket.
Technical parameters
- Weight: 842 g
- Internal volume: 40 liters
- Outer volume: 11,5 liters
- Load capacity: up to 18,1 kg
- Back panel width: 27,9 cm
- Height of the fully unrolled backpack: 80 cm
- Top circumference of the backpack: 95,3 cm
- Bottom circumference of the backpack: 85,1 cm
The listed specs are for size Medium.
Materials
The main part of the Hyperlite Mountain Gear Southwest backpack is made from a new material. Dyneema® Woven Composite 3.9, which brings a combination of low weight, high strength, and top-notch abrasion resistance. Thanks to the fully woven outer layer made of Dyneema® fibers, the material is incredibly strong and durable, feels nicer to the touch, holds its shape better, and doesn't make annoying noises even in cold weather.
The material itself is 100% waterproof, but the stitching can create tiny holes. Even though more than 90% of the seams are taped, it can't be considered 100% water-tight. For complete protection against water and moisture, we recommend adding a waterproof bags.
The side pockets of the backpack, the pockets on the hip belt, and the large front pocket are made from highly durable and sturdy Hardline material with Dyneema®, which can handle even tough terrain.
How to choose the size?
| Backpack size | Torso length |
| Small | 38-43 cm |
| Medium | 43-48 cm |
| Large | 48-53 cm |
| Tall | more than 53 cm |
If you're unsure about choosing the right size, you can contact us. We'll be happy to help you out.
Product data
Hyperlite Mountain Gear Southwest 40 (2025)
Usage
SizeM
ColorBlack
Weight842 g
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SexUnisex
Maximum load capacity18,1 kg
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Material compositionUltra-high molecular weight polyethylene (UHMWPE), Nylon, Polyester
MaterialHardline with Dyneema, Dyneema Woven Composite 3.9
value-undefined.options.option-dimensions.name
Internal volume40 l
External volume11,5 l
Volume51.5 l
SizeS, M, XL, L
Other
ColorBlack
ManufacturerHyperlite Mountain Gear
We will help you with your selection
If you are unsure about which size or color to choose, or if you have any other questions, feel free to contact us via email or directly in the online chat. We are here for you.
DC
Customer support
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