This has got to be one of the most expensive rear derailleurs you can hang off the back of your MTB (and part of the super expensive XTR Di2 group).
This version features the medium cage (long cage is available as well) and all XTR Di2 derailleurs have a clutch. High-low limit screws are now allen bolts. The parallelogram, clutch mech, cage and jockey wheels look identical to the non-electronic XTR 11 speed RD, but the b-knuckle is unique and houses the electronic actuator.
Weight on my scales is 288g.