Macintosh OS 9 Sherlock 2 Update CD Install Disc 9.1 Mac OS 691-2746-A
Pictures are of the last of the OS 9.1 I have.
As can be seen the disk and surface appear almost new, perhaps disc used once or twice.
I seem to remember its possible to download a free upgrade to OS 9.2 if desired.
Perhaps info can be found at
https://www.macintoshrepository.org/814-mac-os-9-updates-en_us-
Shipping includes delivery confirmation and tracking.