The Shimano Alivio RD-M3100 Rear Derailleur features Shadow RD technology to keep the derailleur safe from trail obstacles.

• Super low profile Shadow RD technology
• Rear Derailleur Mount Type: Shimano Rear Direct Mount
• Rear Derailleur Mount Type: 10×1 Standard
• Rear Der/Shifter Compatibility: Shimano Mountain
• Cage Length: Long
• Drivetrain Speeds: 9
• Chain Wrap Capacity (teeth): 45
• Largest Cog: 36