The left mirror is mandatory on the scooter, you will soon find out why if you ride without it.
Keep it safe and install a new mirror if necessary.
In addition, there is of course the dire need to replace the mirror if it no longer matches the styling of your cruise missile.
This is the original left mirror for the GTS models introduced in 2023, but it will undoubtedly fit many other scooters and motorcycles. The thread is M10, left-turning.
