Shimano Di2 EW-RS910 A E-Tube Junction for Bar / Frame - Dura Ace / Ultegra / GRX
E-TUBE Junction A - Built-in type for frame or handlebar
Designed for use as a bar-end on drop handlebars or with designated frames, the RS910 junction is a 2-port option for internal E-TUBE wire routing, charging, battery monitoring, and shift mode switching.