I just sold my 2011 GS Adventure (and my RT a few years back), and no longer need my GS-911.
This is the yellow bluetooth professional model. If you use an iPhone and want to use this on the road, I'd say pass. Android, generally it will work see: https://www.hexcode.co.za/products/gs-911/support/faq/does-it-run-on-my-android
My units serial number starts with gs6xxxx.
If you're doing stuff in your garage then it's all a non-issue because you use USB.
Anyhow, Asking $500 for the unit.