9 speed design. Double Only Construction: The first double specific derailleur accommodates a wide 36 x 22 double specific gearing. Tire and Frame Clearance: The new design allows for super wide tires, steep chainstay angles, and less chain drag due to a compact, re profiled cage. Dual Pull Design: Compatible with top or bottom routing Compact Design: Allows for super wide tires steep chainstay angles with less chain drag. Compatibility: Crankset FC M815 2 for 83mm bb shells and low clamp frame designs. Multi clamp to fit 28.6 34.9mm frames Top gear teeth: 36.