Mammut Aconcagua Light ML Mens Fleece Jacket

I bought a size M, Mammut Aconcagua Light ML fleece for winter walking in the mountains a few weeks ago. So far only tested in Sydney with a 10kg pack on sunny, windy days. I run hot so usually strip to a base layer when warm. Too early to discuss robustness, etc. It’s a close fitting, simple very light jacket. Just two pockets. No frills like thumb holes (which I hate). My only criticism is the sleeves are extremely long. Yes they cover your arms when climbing, keep your hands warm and can be pushed up but they come down to your fingers when standing. I’m a 173cm MAMIL with a 100 cm chest and 74kg.

I did a 15 km walk with the jacket on - weather was “feels like 6-10C with wind chill”. The jacket is thin but amazingly warm for its weight. I had an icebreaker cool-lite baselayer. Although the jacket breathes, and the pockets zips open to ventilate, I found myself sweating. On the plus side, I’m pleased with it drying/wicking quickly. Also, despite the wind, I didn’t feel the need for another layer. With a GTX hard shell on I would be toasty but damp. I did take it off briefly but wanted to keep my core warm. In contrast, I wore the heavier model Aconcagua ML on the same walk and after 3km it stayed in the bag.

So, in summary, I feel it will be a great approach fleece for alpine hiking. In proper cool weather I could throw a a shell over and not overheat. You will need a warm layer if you stop to rest/camp if the temperature is in single digits, but that’s expected. Having spent the last few years using merino, I am happy to have a compact, comfortable and very quick drying jacket. It comes out of a washing machine almost dry.

I bought a light gray colour, the red was almost fluorescent orange.

Well recommended by PAST Outdoors in Helensburgh.

This is a great jacket for everyday activities. I use it as an outer layer +10c or as a mid layer in colder conditions. It’s light, comfortable and looks great.
I’m 183cm and 84kg, size M fits me perfectly.