Shimano Di2 Junction-A Box 5-Port



Model: Dura-Ace
3 Port5 Port


Shimano has simplified and improved the front junction box (junction A) for Di2. The new Di2 unit utilizes a rubber strap that cleanly and aerodynamically fastens underneath the stem. The junction box has a charging port that makes it possible to charge both internal and external batteries without having to remove them from the bike.

Features of Di2 Junction-A Box

  • 5-port junction box
  • E-tube compatible
  • Battery charging port for use with Shimano ISMBCR2 charger
  • Shimano part# ISMEW90B
Model Number
Item Code
Shimano Di2 Junction-A Box 5-Port