Garmin Varia RVR315 Rearview Radar

Keep an eye on traffic behind you — detects approaching vehicles up to 153 yards (140 meters) away. The unit pairs seamlessly with your Edge® bike computer, compatible smartphones, select Garmin wearables or the dedicated radar display unit. When connected to a compatible smartphone, the Varia™ app presents visual graphics and issues tone and vibration alerts to warn of approaching cars. Varia radar data can also be shared with third-party apps such as Ride with GPS to overlay rear-traffic alerts on your maps. Rechargeable battery provides up to 7 hours of run time.