Shimano's electric wire cables for Di2 groupsets.

Length Guide for typical internal Di2 setup
Shifters to Junction A (stem): 350-500mm x2
Junction A to Junction B (internal): 1200mm
Front Derailleur to Junction B: 350-500mm
Rear Derailleur to Junction B: 750mm
Internal Battery (seatpost) to Junction B: 750mm

Length Guide for Handlebar Junction setup 
Shifter to Handlebar Junction A: 350mm
Shifter to Shifter: 750mm
Shifter to Junction B (internal): 1200mm
Front Derailleur to Junction B: 350-500mm
Rear Derailleur to Junction B: 750mm
Internal Battery (seatpost) to Junction B: 750mm

Please note this guide is intended to be used as reference only. Required cable lengths will differ depending on setup and frame size.

Specifications
For internal wire routing

Mfr Claimed Weight
TBC