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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

Shimano Rear Derailleur Pulley Assemblies

Shimano's Di2 electric drivetrain takes shifting to the next level. Two Di2 Battery Chargers are available. Choose the model designed for your system's battery. An additional power cable is required for the external-style battery charger (sold separately). These chargers fully charge the battery in 90 minutes.

Get that nice derailleur shifting smoothly and operating silently again with a Shimano Rear Derailleur Pulley Set. - OEM pulley set for XTR RD-M9000 - Sealed bearing guide & tension pulley - Guide pulley with extra long teeth for increased chain control