Garmin Varia RTL515, Cycling Rearview Radar with Tail Light, Visual and Audible Alerts for Vehicles Up to 153 Yards Away - 010-02376-00

Look into the Garmin varia radar! https://amzn.to/4a4gcJR Huge safety game changer. I got a super squishy seat and have not regretted it! Cloud-9 was the brand.