Through SEIS, the electronic rear derailleur is the fastest & most precise shifting available for the road.  In addition, the carbon pulley plate is lightweight and rigid while adding a dash of style.

Model Number: RD-7970
Series: Dura-Ace 
Cassette Compatibility: 10-speed
Maximum Sprocket: 27T
Minimum Sprocket: 11T
Maximum Front Difference: 16 teeth or less
Total Capacity: 32 teeth or less
Guide Pulley: -
Tension Pulley: -
Bracket Body: Aluminum
Bracket Pivot Seal: -
Plate Body: Engineering Composite
Plate Pivot Seal: -
Outer Link: Aluminum
Inner Link: Aluminum
Link Pin Bushings: -
Outer Plate: Carbon
Inner Plate: Carbon
Average Weight: 225g