I'm tempted to get one of those skull caps for the colder weather for when the headband isn't enough cuz rite now and for years I've been using thin knit watch caps - the short ones you don't have to fold over. I've tried on many cycling skull caps at bike shops and I remember the fit and feel varying quite a bit. Some were too tight or too thick. I think buying on-site at an LBS is the better idea. I did the same with my pearl izumi cycling headband and am very happy with it. At the back it says micro s sensor. I think it is one of these.

http://www.amazon.com/s/ref=nb_sb_no...headband&ajr=0