The SW-R610 are 2 electronic Di2 sprint shifter for any positioning at the handlebar e.g. in the drop section underneath the handlebar tape. Left switch for up shifting and right shift for down shifting.
Note: In order to ensure proper functioning of the electronic Di2 drive system, all components require the same firmware version. The optional diagnostic device allows for reading out or updating the firmware version. An operation of components with different firmware versions may cause a malfunction or loss of function.