The new Shimano EC300 charging connector is designed specifically for Shimano's 12-speed Di2 road drivetrains. Connected via the rear derailleur, it is also compatible with Shimano power meters. Charging of the new Shimano 12-speed Di2 road drivetrains is now accomplished with the EC300 charger cord. Attached to the rear derailleur, this new cord is less expensive than previous chargers and can also be used to charge Shimano power meters.Di2 charger cable for the internal battery that will keep your Di2 system shiftingDi2 uses a powerful long-life 7.4V Li-Ion battery: keep it in top condition and ready for shifting with this specific Shimano Di2 charger1.5 hour charge timePlugs in directly to RDR9250 rear derailleur