Slimmer, lighter axle design. SPD means efficient power transmission and the Shimano XTR PD-M9000 is no excepetion.
Shimano XTR: The new XTR M9000 series presents the most advanced XTR mountain bike components and tyres ever. Excellent mud-shedding properties means that you needn't worry about your pedals clogging up or losing efficiency. The PD-M9000 is the culmination of Shimano's expertise in bearings, pedaling dynamics, and the reliability of SPD. Simply put: It is the benchmark.
larger contact area for shoe
stain-resistant design with oval shaped axle housing
Adjustable release hardness
Chromoly axle with low-maintenance, sealed cartridge axle system