Shimano FD-M815 Low-Clamp Front Saint Derailleur, 28.6/31.8/34.9 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 chain stay angles, and less chain drag due to a compact, re, profiled cage Dual Pull Design: Compatible with top or bottom routing Compatible with 9 speed chain Shimano Reference Number: FD,M815