XT Shadow ES 12-speed wireless rear derailleur for the ultimate in shifting performance and durability. Precise and clean wireless shifting with Integrated on-board removable battery (BT-DN320 sold separately) . The integrated removable on-board battery is protected within the linkage. Crash recovery function, absorbs impacts and returns to its original position. Connectivity BLE, ANT private. Shadow ES features a super low profile skid plate design and optimized slant angle for optimal clearance.