Winner of the 2021 Backpacker Editors’ Choice Gold Award. You come to the trailhead fully prepared, you expect the same reliability and readiness from your pack—and the Aether 55 delivers. Custom Fit-on-the-Fly® Shoulder Straps and Hipbelt, and an adjustable torso provide a near-perfect fit while an injection-molded backpanel offers close-to-body performance. Made with bluesign® approved nylon and PFC-free DWR. Raincover included.
Load Range:
S/M:
L/XL:
Fabric:
Contact us within 30 days of receiving your goods to request a refund or exchange if products are eligible (see: Return Policy).
All packaging or products must be in their original, re-sellable condition.
Outlet sales are final and can only be returned for exchange. Items found faulty or under warranty will be replaced or refunded.
Some special condition products are labelled as No Refund & Exchange Products. Sale of these items are final and are not eligible for neither refunds nor exchanges.
For safety reasons, K2 cannot accept returns on climbing equipment, socks, underwear and some other products unless faulty.
Please check out our refund policy if you need more information.
Torso Sizing
1- Find Iliac Crest - Top of hip bone.
2- On back of neck, find C7 vertebra. Touch your chin to your chest and feel the large protruding bone at the base of your neck.
3- Measure - from C7 vertebra to the iliac crest to determine torso length.
Hipbelt Sizing
To determine hipbelt size, measure around the hips at the iliac crest, not the waist. The padded portion should wrap well around the hips, leaving a gap of 3" to 6" between the tips of both hip pads when securely tightened.
| Outdoor Packs Torso Sizes | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | 23" (58.5cm) | 24" (61cm) | 25" (63.5cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Aether Plus | Aether | - | - | - | S/M | S/M | S/M or L/XL | S/M or L/XL | S/M or L/XL | L/XL | L/XL | ||
| Aether Pro | - | - | S | S | S or M | S or M | M or L | M or L | L | L | - | |
| Atmos AG™ | - | - | - | S/M | S/M | S/M OR L/XL | S/M OR L/XL | S/M OR L/XL | L/XL | L/XL | - | |
| Atmos AG LT | - | - | - | S/M | S/M | S/M | S/M | L/XL | L/XL | L/XL | - | |
| Talon | Talon Pro | - | - | S/M | S/M | S/M or L/XL | S/M OR L/XL | L/XL | L/XL | - | - | ||
| Rook | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | |
| Volt | - | - | - | O/S | O/S | O/S | O/S | OS | - | - | ||
| Exos | - | - | - | S/M | 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 | L/XL | - | |
| Kestrel | - | - | S/M | S/M | S/M | S/M or M/L | S/M or M/L | M/L | M/L | M/L | - | |
| Osprey UNLTD AG 32 | - | - | - | S/M | S/M | S/M or L/XL | S/M OR L/XL | L/XL | L/XL | L/XL | - | |
| Stratos | - | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | |
| Soelden Pro | Soelden | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | |
| Kamber 20,30 | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - |
Talon 6 O/S HIPBELT FIT RANGE IS 25-50" (64-127 CM)
| Hydration Packs Torso Sizes | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | 23" (58.5cm) | 24" (61cm) | 25" (63.5cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Manta | Skarab | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | |
| RAPTOR | SYNCRO | SISKIN | KATARI | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - | |
Duro LT, 6, 1.5 SMALL (30-35" / 75-90 CM.) MEDIUM (35-41" / 90-105 CM.) LARGE (41-47" / 105-120 CM.)— CHEST MEASUREMENT
Duro 15 S/M (30-41" / 76-104 CM.) M/L (41-47" / 104-119 CM.) — CHEST MEASUREMENT
| Travel Packs Torso Sizes | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | 23" (58.5cm) | 24" (61cm) | 25" (63.5cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Farpoint Travel Pack | - | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | |
| Farpoint Trek | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | |
| Ozone Duplex (M) | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | |
| Interchangable Hipbelt - Men's Xenith/Aether AG | |
|---|---|
| XS 25-25" / 60-114 cm | M/L 28-45 " / 70-127 cm |
| S 25-25" / 60-114 cm | L 29-55" / 72-140 cm |
| S/M 36-45" / 65-114 cm | O/S 25-50" / 64-127 cm |
| M 27-48" / 69-121 cm | |
| Outdoor Packs Torso Sizes | 11" (28cm) | 12" (30.5cm) | 13" (33cm) | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ariel Plus | Ariel | - | - | XS/S | XS/S | XS/S | XS/S or M/L | XS/S or M/L | M/L | M/L | M/L | - | - |
| Ariel Pro | - | - | - | XS | XS | XS or S | XS or S | S or M | S or M | M | M | - |
| Aura AG | - | - | XS/S | XS/S | XS/S | XS/S or M/L | XS/S or M/L | M/L | M/L | M/L | - | - |
| Aura AG LT | - | - | XS/S | XS/S | XS/S | XS/S or M/L | XS/S or M/L | M/L | M/L | M/L | - | - |
| Tempest | Tempest Pro | - | - | - | XS/S | XS/S | XS/S or M/L | XS/S or M/L | M/L | M/L | - | - | - |
| Renn | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Viva | - | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Eja | - | - | XS/S | XS/S | XS/S | XS/S or M/L | XS/S or M/L | M/L | M/L | M/L | - | - |
| Eja Pro | - | - | XS/S | XS/S | XS/S | XS/S OR M/L | XS/S OR M/L | M/L | M/L | M/L | - | - |
| Kyte | - | - | XS/S | XS/S | XS/S | XS/S or S/M | XS/S or S/M | S/M | S/M | S/M | - | - |
| Osprey UNLTD AG 32 | - | - | XS/S | XS/S | XS/S | XS/S or M/L | XS/S or M/L | M/L | M/L | M/L | - | - |
| Sirrus | - | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Sopris Pro | Sopris | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Kresta 20, 30 | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - |
Tempest 6 O/S HIPBELT FIT RANGE IS 24-44" (61-112 CM.)
| Hydration Packs Torso Sizes | 11" (28cm) | 12" (30.5cm) | 13" (33cm) | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mira | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - | - | |
| Skimmer | - | - | - | - | O/S | O/S | O/S | O/S | - | - | - | - | |
| Raven | Sylva | Salida | Kitsuma | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - | - |
Dyna LT, 6, 1.5 SMALL (26-30" / 65-75 CM.) MEDIUM (30-35" / 75-90 CM.) LARGE (35-41" / 90-105 CM.)— CHEST MEASUREMENT
Dyna 15 S/M (26-35" / 66-90 CM.) M/L (35-41" / 90-104 CM.) — CHEST MEASUREMENT
| Travel Packs Torso Sizes | 11" (28cm) | 12" (30.5cm) | 13" (33cm) | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Farpoint Travel Pack | - | - | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - | |
| Fairview Trek | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - | |
| Ozone Duplex (W) | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - | |
| Interchangable Hipbelt - Women's Xena/Ariel AG | |
|---|---|
| XS 24-45" / 60-114 cm | M/L 28-50 " / 70-127 cm |
| S 25-45" / 60-114 cm | L 29-55" / 72-140 cm |
| S/M 26-45" / 65-114 cm | O/S 25-50" / 64-127 cm |
| M 27-48" / 69-121 cm | |
| Outdoor Packs Torso Sizes | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | 23" (58.5cm) | 24" (61cm) | 25" (63.5cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hikelite 18, 26 | - | O/S | O/S | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Hikelite 28, 32 | - | S/M | S/M | S/M | S/M or M/L | S/M or M/L | M/L | M/L | M/L | - | - | - |
| Glade 5, 12 | - | - | - | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Osprey Sportlite 15, 20 | - | O/S | O/S | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - |
| Osprey Sportlite 25, 30 | S/M | S/M | S/M | S/M | S/M or M/L | M/L | M/L | M/L | M/L | - | - | - |
| Mutant 22 | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - | - | - |
| Mutant 52, 38 | - | S/M | S/M | S/M | S/M or M/L | M/L | M/L | M/L | - | - | - | - |
| Mutant Nimsdai 90 | S/M | S/M | S/M | S/M OR M/L | M/L | M/L | M/L | M/L | - | - | - | - |
| Zealot 30 | - | - | O/S | O/S | O/S | O/S | O/S | - | - | - | - | - |
| Zealot 45 | S/M | S/M | S/M | S/M or M/L | M/L | M/L | M/L | M/L | - | - | - | - |
| Hydration Packs Torso Sizes | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | 23" (58.5cm) | 24" (61cm) | 25" (63.5cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Raptor Pro | - | - | - | O/S | O/S | O/S | - | - | - | - | - | - |
Duro Dyna Belt O/S HIPBELT FIT RANGE IS 24 – 45" (60 – 115 CM)
Savu O/S HIPBELT FIT RANGE IS 26 – 50" (66 – 127 CM)
Seral O/S HIPBELT FIT RANGE IS 26 – 50" (66 – 127 CM)
| Child Carrier Packs Torso Sizes | 14" (35.5cm) | 15" (38cm) | 16" (40.5cm) | 17" (43cm) | 18" (46cm) | 19" (48cm) | 20" (51cm) | 21" (53cm) | 22" (56cm) | 23" (58.5cm) | 24" (61cm) | 25" (63.5cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Poco, Poco Plus, Poco LT | - | O/S | O/S | O/S | O/S | O/S | O/S | O/S | - | - | - | - |
Regular Fit:
XS 24-25" / 60-114 cm
S 24-25" / 60-114 cm
S/M 26-45" / 65-114 cm
M 27-48" / 69-121 cm
M/L 28-50" / 70-127 cm
L 29-55" / 72-140 cm
O/S 25-50" / 64-127 cm
Extended Fit:
S/M EF 17-20.5" / 43-52 cm
L/XL EF 19.5-23" / 49-58 cm
O/S EF 40-70" / 101- 177 cm
WXS/S EF 13.5-17" / 34-43 cm
WM/L EF 16-19.5" / 40-49 cm
