With the new M8100 version of the XT, Shimano has upgraded the group to 12 speeds and been above most other things in terms of design, function and weight. Therefore, in the M8100 you get almost an XTR group for XT price.

The rear derailleur is 12-speed up and fits all Shimano's 12-speed units.

Can take over 51 teeth on the cassette (can take down to 10 teeth on the smallest gear wheel).

With long arm.

Large 13-speed gear wheel with closed bearings.

Shadow +.

The rear derailleur is for an exchange that fits with having 1 blade on the crankset.