Let Garmin watch your 6. The RTL515 taillight gives your bike radar for what's coming up behind you. Using ANT+ or Bluetooth® Smart to talk to your Edge or your phone, the RTL515 displays approaching cars on the screen. The powerful LED makes sure that drivers are aware of you. Great for long rides on quiet roads where you might need the RTL515 to snap you back to the reality of an approaching vehicle. When riding busy streets, the radar will tell you what you already know – you’re surrounded by cars, but you can still use it as a standalone bike light. In light only mode, you can control the unit from your paired device, or with the 1-button control on the light itself.