I installed Skene P3 lights with Decelerometer & Turn Signals on my 2021 F900 R. I think they are superb lights. They are very bright and functional, greatly increased the bike's indicator lights to following vehicles (if the driver is paying attention). I tied into the wiring harness under the seat, just below the tool kit location. The brake light should be the gray/black/yellow dots wire. Skene has the wiring diagram on its website. The 900 seems to align with the F800GS with LED light.