Part of Shimano's final 27 speed Groupset M770/M775 - these 9x27 speed groups were originally marketed as Mega9 or simply M9.
Lightweight 4 arm spider, close ratioed 11-32 varient.
It originally came on a new bike, it was swapped out for a wider ranged cassette before it got as far as the trails!
If you look very carefully you might be able to see a few chain witness marks from its original fit up (and the few k's it covered) It is to nearly all intents and purposes as good as new IMO. (Please check out the photos)
Any questions (or sensible requests) AT ALL please just ask.
International shipping via Ebay's global shipping programme.
Check out my collection of quality retro Shimano MTB componentry. (LOADS more to be listed)