https://www.geeky-gadgets.com/blink-saddles-with-integral-brake-and-rear-lighting-28-04-2017/
Cyclists who take to the busy streets during the hours of darkness or in low light, or would just like to be seen a little more easily, may be interested in
rear lightingblinksaddlesintegralbrake
https://www.hella.com/soe/en/News/FORVIA-HELLA-sets-the-scene-for-rear-lighting-on-city-and-intercity-buses-6688/
FORVIA HELLA sets the scene for rear lighting on city and intercity buses
rear lightingforviahellasetsscene