Garmin Varia RTL 516 - STVZO approved rear light with radar technology for detecting approaching vehicles from up to 140 m, display/warning on Garmin wheel computers/watches/via app, 16 hour battery : Amazon.de:
Varia Rearview Radar RTL515/RTL516 - Varia RDU Device Overview
Garmin Varia RTL516 Radar with Bike Rear Light - black | BIKE24
Garmin GARMIN VARIA RTL 516 BIKE TAIL LIGHT + RADAR