This was taken off an almost new bike with less than 200 miles on when upgraded to Di2. Condition is as nearly as new with exception of tiny scratch.
Shimano 105 RD-5700-GS Rear Derailleur The all-new Shimano 105 RD-5700-GS rear derailleur was designed to provide awesome shifting under all conditions. Its wide link design increases rigidity and reliabilty, and is engineered for long-term quality.
Positive, precise shifting under all conditions 10-speed SIS Wide gear ratio with enhanced cable pull mechanism is compatible with 28T cassettes AND compact cranks - no need to change your rear derailleur! Stiffer, wide outer link design suppresses flex to give you sharp, precise shifts that are faster, smoother and stable Designed for reliability and durability