Built for the short and long haul with expandable capacity and premium features to keep all your options open.
A pack that’s as practical, versatile, and as ready to go and conquer as you are.
The bag that started it all, the ALPHA 31 is purposefully built for a wide range of adventures, both big and small. With expandable capacity, multiple lash points, external fast-access pockets, and three access points to the main compartment, it's a hardy pack with a unique blend of attributes that enables independence and self-reliance.
Using 100-percent recycled ECOPAK™ fabrics from Challenge Outdoor allows the ALPHA 31 to be lightweight, durable, waterproof, and eco-friendly. The updated roll top includes a triple-fold to lock out elements, and all exterior panels feature water-resistant rain flaps and YKK® Aquaguard® zippers. When you need extra space, the roll top increases the ALPHA's capacity by five liters. Inside the main body, there's a 15" padded laptop sleeve and four additional pockets to securely hold important gear.
The ergonomic shoulder straps feature dual-density foam and a back panel designed to conform to your shoulders and chest. Every touchpoint the ALPHA 31 has with your body improves airflow and comfort.
Primary access and expandability are provided by the roll top. A second front access panel provides access to items lower in the bag or can become the primary access when used for light to medium loads.
From the demanding world of sailing and kiteboarding comes Challenge Outdoor ECOPAK fabric. Made of abrasion-resistant 100 percent recycled polyester, ECOPAK absorbs 80 percent less moisture and has better UV resistance and color retention than traditional laminated nylon.
All Challenge Outdoor ECOPAK fabrics used in the Alpha 31 have a waterproof rating of 200+ psi, meaning it's a bag equipped to keep what's inside dry in rain, snow, bogs, marshes, and faraway jungles. All openings employ rain flaps or weather-resistant YKK Aquaguard® zippers.
ITW is one of the original developers of the modern sr buckle. Their hardware is trusted the world over and used on the Alpha 31 for its quality and dependability.
The Alpha 31 features a roll top that can expand up to 36 liters to accommodate large loads. When lightly loaded, the compression straps can be pulled in and top rolled down to minimize the bag’s bulk.
Alpha 31 is equipped with a hydration loop, tube port and tethers, ready to hold up to a 3 liter bladder.
Laptop sleeve can hold up to 16” laptop. Device can be loaded from exterior side access or from the interior pocket.
Removable reflective ties provide night visibility while a loop on the bag base is ready to hold a bike light.
For maximum interior visibility, the Alpha 31 employs laminated fabrics with white backings for a bright and visible interior.
A .060” high density polyethylene frame sheet provides structure and stability to the bag body. To decrease weight or increase flexibility, frame sheet is removable.
Back panel and shoulder straps use a low-abrasion woven for comfort and durability.
Tool loops and reflective bungee cords allow tethering of trekking poles, helmets or tools.
|Weight||3.3 LBS (1.5 KG) - Black|
|Length, max||21.5 in.|
|Width, max||11.5 in.|
|Depth, max||7.5 in.|
|Overall Dimensions||21.5" x 11.5" x 7.5" (54 x 29 x 20cm). Back panel height is 21.5" (54cm).|
|Laptop Sleeve||16" side access|
|Volume||31 liters (expandable to 36 liters)|
|Body Fabric||Challenge Outdoor EPX600 (Black), EPX400 (Duffel Green), EPLX600 (Multicam® Black)|
|Liner Fabric||Challenge Outdoor EPX70RS|
|Frame Sheet||0.060" thickness high density polyethylene (white)|
|Webbing||Nylon weave style MIL-W-17337|
|Zippers||YKK® Aquaguard®/YKK® RC coil|