Box Components Extra-long rear derailleur Three Prime Chape

The Box Three rear derailleur simplifies the features of the Prime 9 Box One and Two rear derailleurs, making it a complete, user-friendly rear derailleur. Featuring a limited-slip clutch, sealed-bearing pulleys and solid construction, Box Three rear derailleurs are compatible with 11-46 and 11-50t derailleurs, making them one of the most versatile derailleur offerings for Prime 9.