Shimano BT-DN320 DI2 Rear Derailleur Battery Brand_Cyclonus adding some extra visibility in

adding some extra visibility in low light

giving you a more responsive front wheel and more control

ALUXX Aluminum Technology

Controller: Mode support switch from SRAM bonus button

Shimano BT-DN320 DI2 Rear Derailleur Battery Brand_Cyclonus adding some extra visibility inDi2 REAR DERAILLEUR BATTERY BT DN320 Full wireless technology means an all new battery. The BT DN320 fits snuggly and protected within the new wireless XTR rear derailleur and powers the fast and smooth shifting XTR is known for. FEATURE Protected Battery: Tucked safely inside an enclosed space, the battery wont budge even in rough terrain, while remaining completely removable for charging. Longevity: 305 mAh provides for more riding on one charge.