I recently purchased a helmet-mounted "tail" light that works really well with the relatively low profile of my new sofrider - not only does it sit on top of my helmet, it actually self levels and maximizes the visibility for oncoming drivers/vehicles. It is called the "Planet Bike Blinky "3H" 3-Led Rear Bicycle Light with Self Leveling Helmet Mount". I use this in addition to the tail light that is mounted to my luggage rack.