SHIMANO Derailer - Rear - Deore (model M591), black

The Toyota Camry of wide-range rear derailers. Shifts to 36t.  For 9 speed cassettes.  

Shimano code name RD M591 SGS, in which RD = rear derailer; M=Mountain bike series; 591 = the numerical grade in the shimano numerican hierachy that used to go to 7XX, but now it's up the 9XX.

---------Feb 4, 2020 NOTE:

These were available in silver but Shimano decided to stop making those - drat...  These black M591 derailleurs will also go away forever, supposedly sometime later this year, unfortunately. 

--June 2022 - The black M591 derailleurs have now been discontinued by Shimano, too.  But we have lots on backorder and they continue to trickle in from time to time.