Mens Gamma Jacket-Softshell Jackets-Arc'teryx-Mongoose-Mountain Sports
Arc'teryx

Men's Gamma Jacket

Weather-resistant softshell jacket for hiking and mountain activities.

$280
Color: Mongoose
Also inMen'sMen's
Size:
Size guide
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Top features
Brushed backer adds warmth and soft comfort
Recycled Wee Burly™ double-weave nylon face fabric
Shaped cuffs
Description

Hiking, climbing, or skinning uphill—the Gamma Jacket keeps you moving through rugged terrain. Wind-resistant and water-repellent, it shields from the elements while maintaining max breathability on that final summit push. High-stretch material and articulated patterning make overhead movements a breeze, while durable face fabric stands up to rough scrambles.

Perfect for
Trail
Hiking and mountain days.
Wind and weather
Repels the shoulder seasons.
Built to last
Covered by the Arc'teryx warranty.
Features
  • Brushed backer adds warmth and soft comfort.
  • Recycled Wee Burly™ double-weave nylon face fabric. Recycled Wee Burly™ double-weave nylon face fabric for breathable wind resistance
  • Shaped cuffs. Shaped cuffs with partial elastic provide coverage and seal out drafts
  • Stretchy fabric allows you to move more freely.
  • Regular fit provides freedom of movement.
  • DWR (Durable Water Repellent) finish repels moisture. DWR (Durable Water Repellent) finish repels moisture and is free from intentionally added PFAS
Size & Fit
Slim
Regular
Relaxed

Standard fit with room to move. True to size for most.

  • Our classic fit is cut comfortably throughout the chest, waist, hip, and thigh. It allows freedom of movement, provides shape, and layers comfortably over or under our layers.
  • Garment Centre Back Length: Size M is 29"/73.5cm - Varies by size
Open size guide
Materials
  • Body: Fortius DW 2.0 - Woven Double Weave, 186gsm - 88% Nylon, 12% Elastane.
  • Contrast: Terratex™ - 50D Recycled nylon/spandex plain weave, FC0 DWR, 126gsm - 95% Nylon, 5% Elastane.
  • Care: Machine wash low; Tumble dry normal low; Do not bleach; Wash dark colours separately; Do not dry clean; Do not iron; Iron low; Do not use fabric softener; Double rinse.
About the brand

Born in the Coast Mountains of British Columbia, Arc’teryx designs gear built for the wildest weather and the steepest lines. Every jacket, pack, and layer is engineered for precision and performance — because when conditions get real, your gear should too. At Mountain Sports, we love Arc’teryx for its unmatched craftsmanship and commitment to doing more with less, in nature’s harshest playgrounds.

Shop all Arc'teryx

SKU X000010940 · Style X000010940
Size guide

Arc'teryx Size Chart - Men's Apparel

Arc'teryx Sizing Chart

Measurements are in inches, unless otherwise noted. Charts reflect body measurements, not garment measurements.

Men's Jackets & Shirts:

Size Sleeve Chest Waist Hip
XXS 30 33 27 32.5
XS 31.5 35 29 34.5
S 32.5 37 31 36.5
M 34 40 34 39.5
L 35 43 37 42.5
XL 36 47 40.5 46.5
XXL 37 51 44.5 50
3XL 38 54.5 48.5 54

Arc'teryx sizes are intended to fit the body measurements above. If your measurements are between sizes, select a larger size for a looser fit or a smaller size for a tighter fit. Arc'teryx has recently updated the men's fit: medium remains unchanged, smaller sizes now fit tighter and larger sizes now fit looser.

Men's Pants & Shorts (Alpha Sizes):

Size Waist Hip Regular Inseam Short Inseam Tall Inseam
XXS 27 32.5 31 29 34
XS 29 34.5 31 29 34
S 31 36.5 31.5 29.5 34.5
M 34 39.5 32 30 35
L 37 42.5 32.5 30.5 35.5
XL 40.5 46.5 33 31 36
XXL 44.5 50 33 31 36
XXXL 48.5 54 - - -

Men's Pants (Numeric Waist Sizes):

Size Waist Hip Regular Inseam Short Inseam Tall Inseam
28 30 35.5 31 29 34
29 31 36.5 31.5 29.5 34.5
30 32 37.5 31.5 29.5 34.5
31 33 38.5 32 30 35
32 34 39.5 32 30 35
33 35 40.5 32 30 35
34 36 41.5 32.5 30.5 35.5
36 38 43.5 33 31 36
38 40 45.5 33 31 36

Numeric pant sizes correspond to the body measurements shown above. Several Arc'teryx pant models are sized numerically and may be offered in Short, Regular, and Tall inseam lengths - see each product page for the options available.

How to measure: Sleeve - with your arm relaxed at your side and slightly bent, measure from the center back of your neck, across the shoulder, over the elbow and down to the wrist. Chest - with arms relaxed at your sides, measure under your arms around the fullest part of your chest. Waist - measure around your waist at the narrowest part. Hip - standing with feet hip width apart, measure around your hips at the widest part. Inseam - from a standing position, measure from your crotch down the inside of your leg to the floor.
Performance

How it ranks across conditions.

Calibrated against comparable products we stock, so you can compare like for like.

Warmth

Light
Moderate
Warm
Warmest

Brushed-back softshell, no insulation.

Weather protection

Water resistant
Water repellent
Highly weatherproof
Waterproof

PFAS-free FC0 DWR finish sheds light rain.

Breathability

Low
Moderate
High
Very high

Woven face fabric with no membrane.

Packability

Bulky
Moderate
Packable
Ultralight

Brand-stated weight 395g.

Best for

Is this right for you?

Hiking and trail days

Moves well on the up, layers under a shell when the weather turns.

Not for: Sustained heavy rain — this repels, it does not seal.

Shoulder season

The range where a shell is too much and a tee is not enough.

Not for: Deep winter without something warmer underneath.

Everyday wear

Clean enough for town; the fabric stands up to a pack and a car seat.

Not for: Formal occasions.

Full spec sheet

Technical Specs

Style numberX000010940
Weight395g / 13.9 oz
FitRegular
Centre Back LengthSize M is 29"/73.5cm - Varies by size
ContrastTerratex™ - 50D Recycled nylon/spandex plain weave, FC0 DWR, 126gsm - 95% Nylon, 5% Elastane
BodyFortius DW 2.0 - Woven Double Weave, 186gsm - 88% Nylon, 12% Elastane
Country of manufactureIndonesia
VendorArc'teryx
Questions, answered

Before you buy.

Pulled from chats, emails and store visits. The things people actually ask us before they buy. Don't see yours?

Ask a question
How do I wash it?

Arc'teryx specify: Machine wash low; Tumble dry normal low; Do not bleach; Wash dark colours separately; Do not dry clean; Do not iron.

Where is it made?

This style is manufactured in Indonesia. Arc'teryx publish the facility as PT. Yongjin Javasuka Garment II (Hojeon), Indonesia.

How does it fit?

Arc'teryx call this a regular fit. Our classic fit is cut comfortably throughout the chest, waist, hip, and thigh. It allows freedom of movement, provides shape, and layers comfortably over or under our layers.

Will it keep the rain off?

It sheds light rain and blocks wind, which covers most shoulder-season days. It is not a waterproof shell — in sustained rain you want a hardshell over the top.

What does the Arc'teryx warranty cover?

Arc'teryx warrant their garments against defects in materials and workmanship for the practical lifetime of the product. That covers manufacturing faults, not wear and tear or accidental damage. Bring it to us and we will help you start the claim.

Find the right one for you

How the Gamma Jacket compares

Head-to-head against the closest alternatives we stock, so you can see where this one sits before you commit.

Feature
Arc'teryx
Gamma Jacket
You're viewing
Arc'teryx
Gamma MX Hoody
Arc'teryx
Gamma Lightweight Hoody
Weight395g / 13.9 oz585g / 1 lb 4.6 oz350g / 12.3 oz
InsulationUninsulated softshellFleece-backed softshellUninsulated softshell
Main fabricFortius™ DW 2.0 double weave, 186gsmFortius™ 2.0 double weave, 233gsm, FC0 DWRFortius™ DW 1.0 double weave, 125gsm
Weather protectionWind resistant, water repellentWind resistant, water repellentWind resistant, water resistant
FitRegularRegularRegular
MSRP$280$400$260
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