Aconcagua ML Jacket

The Mammut Men's Aconcagua ML Jacket is a magnificent midlayer to mountaineer in. Its Polartec Power Stretch fleece ensures freedom of movement on the mountains, and it wicks moisture and dries quickly for sweaty ascents. The exterior is surprisingly abrasion-resistant so you can wear it without a shell. The thumbholes keep a secure fit when you're layering.

  • Technical midlayer made for mountaineering and skiing
  • Polartec Power Stretch fleece wicks moisture and dries quickly
  • Abrasion-resistant outer offers long-lasting durability
  • Thumbholes secure the sleeves
  • Side pockets are backpack-and-harness-compatible
  • Reviews
  • Q & A

Smallest medium I've ever worn ...

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: Runs small
  • Size Bought: M

Mammut makes good stuff, but it's as if this fleece had shrunk in the washer before it was ever worn. It fits very snugly, by far the smallest size Medium I've ever worn.