Shimano Dura-Ace Ultegra, XTR, and XT Di2 SM-BTR1 battery
The Shimano Dura-Ace Di2 SM-BTR1 battery is a rechargeable 7.4 volt lithium-ion battery for the Dura-Ace Ultegra, XTR, and XT Di2, component system. It mounts to the harness included with the rear wire kit (sold separately) that mounts to the downtube bottle cage bolts and sits just below the bottle cage. This means that you can still use a bottle cage and gives the battery a low center of gravity. The front wire kit (sold separately) has a convenient battery life indicator which is activated by holding down one of the shift buttons. Green means the battery has 50% or more life, Red indicates under 50% of battery life and flashing red indicates an almost drained battery.
Made in japan