System Compatability: Pro Series, HID Series, Classic Plus & Seclect, Evolution & Digital Evolution, HeadTrip & Digital HeadTrip, TrailRat & TrailRat Select, RoadRat, Digital Patrol LED, Digital Patrol, Pre 2001 systems. With NiteRiders Angled Bike Light Helmet Mount, you can attach your bike light to your helmet with straps that go through the vent holes. How you attach the mount will depend on the configuration of the vent holes on your helmet. Adjust the mount for the best angle of vision. Dismount and you can still see the light.