See this pretty girl? She's wearing an invisible airbag helmet which will keep her safe on bike rides. Don't believe me? Watch this video.
The helmet design is dubbed Hövding and while consistently described as "invisible" is just really cleverly hidden:
Hövding is a discreet collar that the cyclist is wearing around his neck. The collar contains a folded airbag which is visible only at a collision. The airbag is designed as a hood that in case of an accident will enclose and protect the cyclist's head. Release mechanism is controlled by sensors that register abnormal movements of the rider in an accident.