Keith from United States, WA Public Profile

I bought this as a shoulder season piece, and a layer when I am on the mountain.
It more than lives up to this goal. It pulls over a t-shirt and allows me to sit around at mildly chilly temps in the high 50s, but pulled over a tight gridfleece and wicking layer it stood up to sub-freezing temperatures with gusty wind. I was actually surprised how well placed the wind resistance was, and how wide the range of temperatures that this is useful at.
It won't stop all wind, and if you are sitting static on the mountain - get out a belay layer. BUT if you are moving, this piece stays warm in a much wider range than expected.
Mammut runs tight, so if you have an american dad bod - or if you want more layers than just a wicking layer - consider going up a size.
Finally - the blue is so vivid. Really great color. I wish they were still making the bright azure, rather than the more subdued blues in their line.