The junction box Di2 SM-EW90-A by Shimano is a connection point for the cockpit area, also known as junction A. It has three E-Tube connectors, a charging connector and is mounted externally under the stem. Its software, which can be kept up to date via the E-Tube platform, determines data such as the current gear position or the battery charge level. The distributor is compatible with all Di2 shifting systems before Dura-Ace R9250 or Ultegra R8150, but not with Dura-Ace 7970 and Ultegra 6770.
The junction box Di2 SM-EW90-A by Shimano is a connection point for the cockpit area, also known as junction A. It has three E-Tube connectors, a charging connector and is mounted externally under the stem. Its software, which can be kept up to date via the E-Tube platform, determines data such as the current gear position or the battery charge level. The distributor is compatible with all Di2 shifting systems before Dura-Ace R9250 or Ultegra R8150, but not with Dura-Ace 7970 and Ultegra 6770.