JensonUSA:

Finally! An XTR level hydraulic disc brake from Shimano. The BR-M965 series of brakes brings hydraulic performance to the XTR line.

Shimano has completely redesigned the hub/rotor interface, resulting in a spline style connector with lockring that is lighter and easier to work on than the IS six-bolt style components. The calipers themselves are a forged one-piece “mono-body” design that eliminates the need for caliper assembly bolts. In addition to saving weight, this design keeps the caliper more rigid, resulting in more positive, reponsive braking.

The Shimano engineered twin piston design provides a balance of sensitive control and high stopping power.

Please note that the rotor included with this item will only work with the new Shimano splined XTR hubs. If you wish to use the caliper with an IS (6-bolt) hub, you must use a different rotor than the one included with this package.