It fits comfortably under other headgear and unobtrusively does its job of keeping the ears and the head warm when it is raw outside

This is the quintessential beanie thin but well made of good material

Its snug and i wear a small in bernbike helmets and have very short hair

Ive used it for running and biking in northern california and i wore it for a few days in a snowstorm in chicago winter and it worked well for me in all three uses