Down jacket with maximum warmth and minimum weight.
The Ama Dablam Jacket is packed full of 800 fill power goose down (125g of down to be precise), one of the best quality downs you can get, making this a very warm but also lightweight option for the cold mountains.
You can feel the weight, or lack of it as soon as you pick it up and it's fully featured as a climbing jacket with the pockets in the right places and gusseted underarms so the jacket won't ride up as you stretch high.