Shimano EW90-B Di2 Cockpit Junction Box 5-Port/ not for Flight Deck

Shimano EW90-B Di2 Cockpit Junction Box 5-Port/ not for Flight Deck. Shimano Di2 Junction Box

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 from http://e-tubeproject.shimano.com/