Firn is a backpack designed specifically for ski mountaineering and moving in demanding mountain terrain, where speed of transitions between the different phases of ascent and descent is key. Thanks to the vest-style fit and well-thought-out alpinist features, the pack adapts perfectly to body movement and does not restrict you.
The lightweight yet durable construction made from a carbonate-coated material ensures the pack can handle harsh snowy conditions without unnecessary weight. The bluesign® PRODUCT certification confirms that environmental and social standards were taken into account during production.
- Innovative ski lasso system
The ambidextrous lasso system allows you to secure skis to the pack without taking it off; the whole process can be done one-handed. If you don’t need the system at the moment, it can be easily removed or stowed away so it won’t get in your way during ascents or climbing. - Vest-style fit with organiser pockets
The shoulder straps are shaped like a vest with pockets for food, a soft flask, a headtorch or technical gear, so your essentials are always within reach without having to access the main compartment of the pack—even while moving in demanding alpine terrain.
- Vest-style fit – perfect close-to-body carry
- Lasso system for carrying skis
- Direct access to the crampons/skins pocket
- Avalanche gear pocket on the front panel
- Removable helmet net in the base pocket
- Top compression strap – also an ice axe stabiliser
- Double attachments for ice axes/poles
- Phone or GPS pocket
- Reinforced ski loop with garage-style stowage
- Cinch closure with protective top flap
- Top rope strap
- Sternum strap with whistle
- Adjustable frames – HDPE framesheet and simple stay
- Snow-shedding back panel made from stretch material
Specifications:
Suspension: HDPE framesheet with a simple HDPE stiffening rod for extra support and rigidity. The framesheet can be easily removed to reduce weight depending on the activity.
Back panel: Atilon foam for structure, ridged EVA foam for padding, covered with a snow-shedding stretch woven fabric
Shoulder straps: vest-style fit with pockets, perforated EVA padding, snow-shedding stretch woven fabric
Sternum strap: with integrated whistle
Hip belt: padded with EVA foam, stretch pocket on the left side, gear loop on the right side
Material: lightweight, durable carbonate-coated fabric
Certification: bluesign® PRODUCT
We offer more than 500 innovative, high-performance Osprey backpacks that reflect a love of adventure and dedication to the outdoors. Osprey backpacks for any adventure and season, we have in stock with free shipping.
The American company Osprey focuses exclusively on the production of backpacks, which is strongly reflected in their high quality, design and technical details and improvements (e.g. Custom Molding System - heat moldable waist belt). In the OSPREY range you will find backpacks designed for several days of demanding treks in the wilderness, as well as a perfectly refined series of backpacks for cycling and for rock climbing fans, and it does not forget about small travellers with a range of technical children's backpacks. Osprey backpacks have won awards from prestigious outdoor magazines such as Backpacker Magazine, Outside Magazine.
Choosing the Right Size for Your OSPREY Backpack
Most OSPREY backpacks are equipped with an adjustable back system that can be lengthened or shortened by up to 10 cm. In addition, there are also standard sizes:
- S/M (M; MD) – for people up to approximately 178 cm.
- M/L (L; LG; L/XL) – for people taller than 178 cm.
New size labels
Some men's backpacks are available in size L/XL. This corresponds to the standard size M/L (L; LG) and is also intended for users taller than 178 cm.
Special models
- EXOS, LEVITY – also available in size S (SM), suitable for shorter men, juniors, and women (approx. 160–170 cm).
Women's Backpacks
Attention! Some women's backpacks are available in two sizes of the back system:
- WS (WXS/WS; XS/S) – for women up to approx. 168 cm.
- WM (WM/WL) – for women taller than 168 cm.
- WL – for women's running backpacks, designed for people approximately 173 cm and taller.
| Back size | 40.5 cm | 43cm | 46cm | 48cm | 51cm | 53cm | 56-58.5cm | 61-63.5cm |
| Aether Pro | S | S | S or M | S or M | M or L | M or L | L | - |
| Aether AG™ | S | S | S or M | S or M | M or L | M or L | L | - |
| Aether AG™ 70 | S | S | S or M | S or M | M or L | M or L | Large or Extra Large | XL |
| Aether (before 2021) | S/M | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Aether/Aether Pls (after 2020) | - | S/M | S/M | S/M or L/XL | S/M or L/XL | S/M or L/XL | L/XL | - |
| Aether Extended Fit | - | S/M | S/M | S/M | S/M OR L/XL | S/M OR L/XL | S/M OR L/XL | - |
| Archeon 70/45 | S/M | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Atmos AG™ (2018-2021) | S | S | S or M | S or M | M or L | M or L | L | - |
| Atmos LT | S | S/M | S/M | S/M OR L/XL | S/M OR L/XL | S/M OR L/XL | L/XL | - |
| Atmos AG™ (2022-current) | - | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Exos (before 2023) | S | S | S or M | S or M | M or L | M or L | L | - |
| Exos (2022-current) | - | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Exos Pro | - | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Kestrel | S/M | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Levity | S | S | S or M | S or M | M or L | M or L | L | - |
| Talon Extended Fit | - | S/M | S/M | S/M | S/M | XS/S or M/L | M/L | - |
| Talon/Pro | S/M | S/M | S/M | S/M or L/XL | L/XL | L/XL | L/XL | - |
| Osprey UNLTD Airscape | S/M | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Osprey UNLTD AntiGravity | S/M | S/M | S/M | S/M or L/XL | S/M or L/XL | L/XL | L/XL | - |
| Zenith | - | - | M | M | M or L | M or L | Large or Extra Large | XL |
| Duro | S/M | S/M | S/M or M/L | S/M or M/L | M/L | M/L | - | - |



