The Garmin Varia RTL515 combines rear radar and a tail light in a single unit. It suits riders on open roads who want both traffic awareness and visibility from one mount. The radar picks up vehicles approaching from up to 140m behind and shows their position and closing speed on your head unit, with an alert as they get closer. The integrated light runs a daytime flash visible up to 1.6km and steps up its pattern automatically when a vehicle is detected, so drivers get a stronger signal exactly when it matters. Battery life runs up to about 16 hours depending on the mode. Key features Rear radar detecting vehicles up to 140m behind Integrated tail light visible up to 1.6km in daylight Automatic light pattern change on vehicle detection Up to 16 hours of battery life Pairs with Garmin, Wahoo and other compatible head units Includes a seatpost mount. Aero posts may need an alternative mount, which we can sort out.