From the manufacturer

The Mammut Aenergy Beanie is a lightweight technical beanie made for high-output alpine activities. Its stretchy ECONYL® recycled nylon fabric manages moisture while providing warmth, and the soft brushed interior adds comfort.

The close-fitting design fits comfortably under a ski or climbing helmet, making it well suited for ski touring, mountaineering, hiking and trail running.

Features

• Lightweight and helmet compatible

• Warm stretch fabric with moisture management

• Soft brushed interior

• Quick drying

• Made with ECONYL® regenerated nylon