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Osprey Exos Pro 55 Litre Ultralight Backpack


Regular price $459.95

Tax included.

Nearly a pound lighter than the Exos 58 and featuring a more fine-tuned adjustment system, the 55-liter Exos Pro is the most comfortable ultralight thru-hike backpack in its weight class. A highly-ventilated AirSpeed™ backpanel supports light loads with ease while maintaining maximum airflow across your back, making it an ideal pack for your most long-distance endeavors on the Appalachian Trail, Pacific Crest Trail and beyond.

Key Attributes


A tensioned mesh backpanel keeps the weight off your back, enabling highly ventilated carrying comfort.


Compression straps and removable lid allow for functional capacity adjustment.


Lightweight fabrics deliver durable performance.


Sheds 74 g / 2.6 oz. when the top lid is removed. An integrated FlapJacket secures the main compartment opening, providing weather protection and load stability when the lid isn't used.


  1. Removable, floating single compartment top lid with key clip
  2. Four webbing lash points on top lid
  3. FlapJacket secures main compartment access and provides weather protection when lid isn't used. Removing top lid reduces carry capacity by 9 L and weight by 80 g
  4. Internal hydration sleeve with center back hose port and Osprey Hydraclip for easier reservoir hanging
  5. Internal compression strap keeps loads stable
  6. Large front fabric compression pocket with stretch side panels accommodates overloads
  7. Multiple front panel lash points for securing extra gear
  8. Lower side compression straps designed to capture sleeping pad on front panel
  9. Deep, dual access stretch mesh side pockets
  10. Dual ice axe loops with handle capture by upper compression straps

Carry Information


  • Lightweight injection-molded ladder provides 4" of torso adjustability, Two-sizes-per-gender design ensures perfect fit and allows for quick, easy adjustment, 3.5 mm powder-coated LightWire frame balances support and dynamic flex


  • 3D-tensioned breathable mesh backpanel ensures supportive fit, Silicone print on lumbar fabric enhances hipbelt grip


  • Shoulder straps combine reverse spacer mesh, die cut EVA foam and a unique structured 3D mesh to deliver excellent support and ventilation, Ventilated mesh yoke evenly distributes load for comfort while maintaining breathability, 15 mm adjustable slide sternum strap with rescue whistle


  • EVA foam padded hipbelt offers dynamic stretch for a secure, dynamic fit, Zippered pocket provides secure storage


Load Range™
5-18 kg

Volumes and Weights

US and International weight and volume specifications

Size cu. in. liter lbs/oz kg.
S/M 3539
55 2.077 .94
L/XL 3722
2.165 .98


Size Height Width Depth
72cm 38cm 31cm
38cm 31cm
Key Fabrics used:
  • MAIN:NanoFly™: 100D Nylon x 200D UHMWPE ripstop, DWR treatments made without PFAS
  • BOTTOM:NanoFly™: 100D Nylon x 200D UHMWPE ripstop, DWR treatments made without PFAS



Sizing and Fitting of your Osprey Pack

Fit is the key to pack performance. Take the time to get it right. Most Osprey packs are available in multiple sizes to fit a range of torso lengths. To find your torso length, have a friend measure your back along the spine (as shown in the picture below) from the level of your iliac crest (the top of your hipbones) to your C7 (the knobby bone at the base of your neck).

Use the table below to determine your pack size.

Exos 58 Litre Backpack Small /Medium Large/Extra Large
Back Length 17-20"/43-51cm 19-23"/48-58.5cm