Polartec Power Stretch is very fast wicking and very stretchy. It can be worn as a midlayer or a base layer. Before merino wool came along it was my favourite base layer fabric in winter and I wore it on many multi-day ski tours. Power Stretch has a smooth outer and a brushed inner that feels soft against the skin. Mammut’s Power Stretch offering is functional and comfortable. I like the extended sleeves with thumb loops, which are excellent for keeping your hands warm. The stretchy fabric means the sleeves can still be pushed up when necessary. The high double-layer collar is warm and there’s a chinguard. The small chest pocket will take a compass but not much more. I’d have preferred handwarmer pockets. The pocket is lined with Power Stretch and there’s a full-length flap inside the front zip so if the garment is worn as a base layer there’s no hard cold zips or rough fabric against the skin. The Aconcagua is close fitting but the high stretch means it’s not restrictive. The weight is quite low but the price is a little on the high side. There’s nothing wrong with this jacket but there are similar Power Stretch ones at a significantly lower cost.



  • Overall: 3-5 out of 5

Pros: lightweight, fast wicking, extended cuffs

Cons: expensive, no handwarmer pockets

  • Details: PRICE Ј125 FABRIC Polartec Power Stretch CLOSURE full-length zip with inner flap CUFFS extended with thumb loops HEM plain POCKETS 1 chest WEIGHT 341 grams SIZES men S-XXL, women XS-XXL mammut.ch
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