Electronics

Shimano BT-R1A External Di2 Battery - All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions - Use Di2 system checker to update component firmware - Di2 External Battery, battery charger, and power cable are universal between Dura-Ace 9070, 7970, Ultegra 6870, 6770 and Alfine Di2 systems - Battery weight: 71 grams

SRAM eTap Battery is the power source for the eTap system. The same power unit is interchangeable between front and rear derailleurs. - Up to 1000 kilometers of riding per charge - Weight: 24g - Finish: Black - Compatibility: SRAM RED eTap