Its thin and stretchy, so fit in the jersey pockets well, its vey tight when you first wear it, it left a mark in my forehead. Not the most comfortable when you sweat, it tends to sticks to your forehead or any bare skins.
The cap is warm and comfortable, but I wish it were shaped, with ear flaps and longer in the back. It rides up on my neck and over my ears. I will probably buy a shaped one before the next cold weather riding season arrives.