Shimano RD-4700 Tiagra 10-speed rear derailleur, GS

From Shimano:

• Offering pro-level features, the 10-speed compatible Tiagra rear derailleur gives high performance at a low price
• Wide link design increases rigidity and service life
• Advanced light action for low-friction shifting up or down the block
• Alloy body's and outer link leads to lower weight without compromising strength and durability
• 11-tooth pulleys for reduced pulley wear and chain noise
• Two fluorine-coated link pin bushings for low-friction performance
• 32 tooth max with triple, 34 tooth max with double chainset
• Compatible with 4700 10-speed road drive systems only