Warmth
The “120” stands for 120 gram SmartLoft insulation throughout the core. That means a 1 meter x 1 meter piece of wool weighs 120 grams, the heaviest the company offers. 

Lining the interior is Smartwool’s namesake merino, which allowed me to wear only a lightweight merino base layer under the Double Corbet 120 and stay warm in temperatures well below 30 degrees Fahrenheit with no wind, during a moderately strenuous uphill snowshoe hike.

Fit & Comfort
Smartwool’s Double Corbet 120 is a slim-fit jacket ideal for those with slender builds, although Smartwool calls it a “regular-fit”. It’s comfortable and moves well with the body.

Features
There’s a lack of technical features in the Double Corbet 120 that may lead to it being seen more often at brunch than deep in the backcountry. Yet, its streamlined fit and inherent warmth certainly warrant its use in moderate wilderness climbs. The chest pocket can handle most size mobile devices and has a nicely stitched cable port.

Quality
The Smartwool Double Corbet 120 is an exceptionally well-built and durable jacket, the best made within the test—it feels “tough”. Testing revealed no physical weaknesses, zipper issues, or exterior blemishes.

Weight
The Double Corbet 120 weighs 17 ounces. It doesn’t pack particularly well. I managed to fold it down to about the size of a football. It will pack reasonably well into the lids of alpine packs in the 30-40 liter range, but don’t expect much else to be in there with it.

Additional Specs
Insulation: SmartLoft Wool Exterior 
Shell: Polyester, Merino wool, with elastane 
Interior Lining: Merino wool