Mammut's Aenergy Beanie is a super soft and stretchy hat to keep you warm when the temperature drops. Special slots to secure your glasses is an innovative feature.
Mammut says:
The Aenergy Beanie is a helmet-compatible and lightweight functional beanie that is a perfect mountain companion. A combination of stretchable material and an anatomical cut means the beanie is a great fit and is very comfortable to wear. The laser-cut slits make it easy to secure your goggles.
Mammut's Aenergy Beanie is a super soft and stretchy hat to keep warm you when the temperature drops. The innovative laser cut slits enable you to safely secure your sun glasses when not required. The subtle raised logo is a classy touch typical of Mammut.
I have a relatively small head and it was a snug fit, I think it would take some wearing in for those with larger heads.