This knitted hat has the power to turn your head into an illuminated Christmas tree. However, it is not battery operated and it is, in reality, meant to be for safety.
The hat is knitted using retro-reflective thread which, like in this case, is lit up by the headlights of the car. It looks totally normal in daylight or even under a streetlight: it glows only in low-light conditions. It will keep you safe and visible if you cycle, run, walk your children from school, etc...
Differently from many Kickstarter projects, these products are available for Christmas: now that is a present with a soul!
More info: kickstarter.com
No batteries and it is meant to keep you safe!
They make snoods/cowl/collars too.