Shimano Sora STI-3500 9s (Double)

Features:

Wide link design for increased rigidity and precise gear shifts
11-tooth pulleys for reduced pulley wear and chain noise
Pulleys feature sintered alloy bushings for smooth-running performance
37 tooth total capacity, rear sprocket size range 11-32T
Compatible with 9-speed drivetrains
Specifications:

Cassette Compatibility: 9
Maximum Sprocket: 32T/14T
Minimum Sprocket: 25T/11T
Maximum Front Difference: 20T
Total Capacity: 41T