Originally Posted By aimless
Because I am bald I generally sleep wearing my beanie even in moderately cool weather, so for me having hard objects embedded in it would not be a good option. This, of course, has no bearing on how useful it would be for anyone else.


Actually you would not even feel anything. The battery holder is very slim and off to the side slightly. It uses 4 cr2032 batteries so the battery compartment is thin.