---
product_id: 2424832
title: "Shimano Ultegra Di2 Internal Routing Junction Box"
price: "C$3076"
currency: NIO
in_stock: true
reviews_count: 8
url: https://www.desertcart.ni/products/2424832-shimano-ultegra-di2-internal-routing-junction-box
store_origin: NI
region: Nicaragua
---

# Seamless electronic shifting integration Internal routing for sleek bike aesthetics Ultra-lightweight at just 0.03 lbs Shimano Ultegra Di2 Internal Routing Junction Box

**Price:** C$3076
**Availability:** ✅ In Stock

## Summary

> ⚡ Power your ride with invisible precision

## Quick Answers

- **What is this?** Shimano Ultegra Di2 Internal Routing Junction Box
- **How much does it cost?** C$3076 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ni](https://www.desertcart.ni/products/2424832-shimano-ultegra-di2-internal-routing-junction-box)

## Best For

- Customers looking for quality international products

## Why This Product

- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Built to Last:** Backed by Shimano’s 2-year warranty for reliable, long-term use
- • **Light as a Feather:** Adds minimal weight, preserving your bike’s speed advantage
- • **Sleek Internal Routing:** Keeps your bike’s look clean and aerodynamic with hidden wiring
- • **Effortless Electronic Sync:** Connects all Di2 components for flawless shifting performance
- • **Universal Ultegra Compatibility:** Designed specifically for Ultegra 6770, 6870 & Dura-Ace 9070 systems

## Overview

The Shimano Ultegra Di2 Internal Routing Junction Box (SM-JC41) is a compact, ultra-lightweight hub that seamlessly connects all electronic shifting wires for Shimano’s Ultegra and Dura-Ace Di2 groupsets. Designed for internal routing, it ensures a clean, aerodynamic bike profile while delivering flawless, reliable electronic shifting backed by a 2-year warranty.

## Description

Shimano’s E-Tube Di2 Junction Box (also known as the B junction) connects all your component and battery wires to make assembly much easier. It's a crucial item along with the five required wire sections to operate your Ultegra 6770, Ultegra 6870, or Dura-Ace 9070 Di2 shift system. The E-Tube Di2 Junction Box is available in two configurations: Internal (SM-JC41) and External (SM-JC40).

Review: Brand new. - A must.
Review: expensive but functional - It is an expensive item for its size but essential to install Di2

## Features

- Crankset Compatibility: 2 x 10
- Compatible Components: Shimano Ultegra Di2
- Recommended Use: ditching your mechanical tethers
- Manufacturer Warranty: 2 years
- Actual Weight Notes: Weight is for Di2 Junction B.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Item Package Dimensions L x W x H | 4.4 x 2.2 x 1.3 inches |
| Package Weight | 0.03 Pounds |
| Item Dimensions  LxWxH | 3 x 4 x 2 inches |
| Brand Name | Shimano |
| Color | One Color |
| Number of Items | 1 |
| Manufacturer | Shimano |
| Part Number | SH4255 |
| Model Year | 2012 |
| Size | Internal/SM-JC41 |
| Sport Type | Cycling |

## Images

![Shimano Ultegra Di2 Internal Routing Junction Box - Image 1](https://m.media-amazon.com/images/I/4116goo9QVL.jpg)
![Shimano Ultegra Di2 Internal Routing Junction Box - Image 2](https://m.media-amazon.com/images/I/41Hn1oLZQeL.jpg)
![Shimano Ultegra Di2 Internal Routing Junction Box - Image 3](https://m.media-amazon.com/images/I/51A70FLdWxL.jpg)
![Shimano Ultegra Di2 Internal Routing Junction Box - Image 4](https://m.media-amazon.com/images/I/51UT4AB5t5L.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Brand new.
*by S***S on October 14, 2025*

A must.

### ⭐⭐⭐⭐⭐ expensive but functional
*by C***S on December 28, 2022*

It is an expensive item for its size but essential to install Di2

### ⭐⭐⭐⭐⭐ Internal wiring junction box - picture is wrong
*by H***X on June 11, 2014*

If you are going to run your Di2 cables inside the frame tues, this is the part you want. The picture is of the external mount box, but the internal box is the one I received. Just remove your crank, plug in your 4 wires, tuck this back into the frame tube, reinstall the protector sleeve and crank and you are all set. A very clean install of shifting perfection!!

## Frequently Bought Together

- Shimano Ultegra Di2 Internal Routing Junction Box
- Shimano Ultegra Di2 EW-SD50 Electric Wire
- SHIMANO EW-RS910 E-Tube Di2 Frame or bar Plug Mount Junction A, Charging Point, 2 Port

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**Shop now:** [https://www.desertcart.ni/products/2424832-shimano-ultegra-di2-internal-routing-junction-box](https://www.desertcart.ni/products/2424832-shimano-ultegra-di2-internal-routing-junction-box)

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*Product available on Desertcart Nicaragua*
*Store origin: NI*
*Last updated: 2026-01-22*