Di2 BT-DN320A Rear Derailleur Battery

Full wireless technology means an all-new Battery. The BT-DN320 fits snuggly and protected within the new Wireless XT and XTR Rear Derailleur and powers the fast and smooth shifting.

• Protected Battery is tucked safely inside an enclosed space, so the battery won’t budge even in rough terrain, while remaining completely removable for charging
• 310 MaH provides for more riding on one charge
• Charger sold separately