The Shimano XTR Di2 Drivetrain Upgrade Kit brings top-level wireless shifting to serious mountain bikers. Whether you&';re racing enduro or riding rugged XC trails, this kit is built for speed, control, and durability. At its core is Shimano&';s new wireless rear derailleur, which delivers fast, precise HYPERGLIDE+ shifting and uses SHADOW ES chain stabilization to stay steady over rough ground. Its wedge-shaped design helps it glance off rocks and trail debris, keeping your ride smooth and your gear protected. Inside the derailleur is the removable BT-DN320 battery, fully enclosed to guard against impacts and vibration while offering long-lasting 310 mAh power. The kit also includes the XTR Di2 shifter, which provides customizable control through Shimano&';s E-Tube app. With its comfortable shape, satisfying button feel, and smart shift modes, the shifter adapts to your riding style for better control and performance. Whether you&';re upgrading for racing or just want a tougher, smarter drivetrain, this wireless Di2 system sets a new standard in high-performance mountain bike shifting. Key Features: Wireless Di2 with Automatic Impact Recovery - Quick, cable-free shifting with automatic motor reset after impacts for steady performance. Wedge-Shaped Derailleur with Protected Battery - Built to bounce off rocks and protect the battery inside. Customizable Ergonomic Shifter - Tactile, programmable controls you can adjust using the E-Tube app.