This is a replacement for the length of cable in the Xiaomi M365 (Standard and Pro) which connects the brake light to the battery.

It plugs into the brake light cable underneath the rear mudguard/fender, and should then be connected to the battery inside the base of the scooter.

This fixes the common fault on these scooters where the wheel (and associated mud/debris) can fray or disconnect the existing brake light cable.