--- title: "FJ Connectors: Compact Optical Fiber In-Line Connector for Internal Connection" description: "The FJ series: Micro Ferrule Joint Connector Ultra-Small, Bayonet lock In-Line Fiber Optic Connector for Internal Assembly" image: https://info.hirose.com/hubfs/Image%20of%20Hirose%20FJ-U%20series%20connector.png --- [![](https://info.hirose.com/hubfs/New-Hirose-Americas-Logo-2023.png)](https://www.hirose.com/us/) - [PRODUCT](https://www.hirose.com/product/) - [ABOUT US](https://www.hirose.com/us/about/) - [COMPANY NEWS](https://www.hirose.com/us/companynews/) - [CAREERS](https://www.hirose.com/us/recruitment/) - [EVENTS](https://www.hirose.com/us/event/) - [CONTACT](https://info.hirose.com/contact) - [BLOG](https://blog.hirose.com) - [PARTNERS](https://www.hirose.com/corporate/en/about/partner) - [Global](https://www.hirose.com/corporate/ja/) - Region Site ▼ - [USA](https://www.hirose.com/us/) - [EUROPE](https://www.hirose.com/eu/) - [CHINA](https://www.hirose.com/cn/) - [HONG KONG](https://www.hirose.com/hk/) - [TAIWAN](https://www.hirose.com/tw/) - [SINGAPORE](https://www.hirose.com/sg/) - [MALAYSIA](https://www.hirose.com/my/) - [KOREA](http://www.hirose.co.kr/) - [PRODUCT](https://www.hirose.com/product/) - [ABOUT US](https://www.hirose.com/us/about/) - [COMPANY NEWS](https://www.hirose.com/us/companynews/) - [CAREERS](https://www.hirose.com/us/recruitment/) - [EVENTS](https://www.hirose.com/us/event/) - [CONTACT](https://info.hirose.com/contact) - [BLOG](https://blog.hirose.com) - [PARTNERS](https://www.hirose.com/corporate/en/about/partner) - [Global](https://www.hirose.com/corporate/ja/) - Region Site ▼ - [USA](https://www.hirose.com/us/) - [EUROPE](https://www.hirose.com/eu/) - [CHINA](https://www.hirose.com/cn/) - [HONG KONG](https://www.hirose.com/hk/) - [TAIWAN](https://www.hirose.com/tw/) - [SINGAPORE](https://www.hirose.com/sg/) - [MALAYSIA](https://www.hirose.com/my/) - [KOREA](http://www.hirose.co.kr/)   ## **FJ Series** **Features: Compact Optical Fiber In-Line Connector for Internal Connection**    - **Space-Saving Design:** Accommodates ferrules with plug diameter of φ5.5mm and jack diameter of φ3.5mm, optimizing space usage while maintaining compact dimensions. - **Wire Tie Capability:** The connector can be tied alongside the wire using a binding band for added organization and stability. - **Easy Mating with Bayonet Lock Design:** The bayonet lock design ensures quick and secure mating, enhancing ease of use and connection reliability. - **Standard LC Connector Ferrules:** Utilizes standard LC connector ferrules, providing flexibility in selecting distributors and cable assembly manufacturers. (Note: Only Multimode Fiber (MMF) is applicable.) [CONTACT US](https://info.hirose.com/contact?utm_campaign=Wearable&utm_source=wearablessources&hsLang=en) [MORE DETAILS](https://www.hirose.com/en/product/series/FJ) [![Image of Hirose FJ-L series connector](https://info.hirose.com/hs-fs/hubfs/Image%20of%20Hirose%20FJ-L%20series%20connector.png?width=487&height=400&name=Image%20of%20Hirose%20FJ-L%20series%20connector.png "Image of Hirose FJ-L series connector")](https://www.hirose.com/en/product/series/FJ) - [![Hirose Electric FJ Catalog Downloadable PDF Image](https://info.hirose.com/hs-fs/hubfs/Hirose%20Electric%20FJ%20Catalog%20Downloadable%20PDF%20Image.png?width=790&height=490&name=Hirose%20Electric%20FJ%20Catalog%20Downloadable%20PDF%20Image.png) **DOWNLOAD CATALOG**](https://info.hirose.com/hubfs/Hirose%20Electric%20FJ_Catalog_ed_FJ_CAT.pdf?hsLang=en) - [![Hirose Electric Surgical Robotics Webinar Video Thumbnail Image 2024](https://info.hirose.com/hs-fs/hubfs/Screenshot_7-11-2024_14555_i9.ytimg.com.jpeg?width=1278&height=718&name=Screenshot_7-11-2024_14555_i9.ytimg.com.jpeg) **WATCH VIDEO**](https://youtu.be/dh_UfGNHfCc) ## **MORE TO EXPLORE:** Advancing Medical Tech with Hirose's Surgical Robotics Solutions LEARN MORE [Learn more about Hirose's comprehensive connector solutions across a wide range of medical applications.](https://hubs.ly/Q02r2zHz0) APPLICATION BLUEPRINTS [Find the perfect Hirose connector for your medical technology and surgical robotics applications.](https://info.hirose.com/surgical-robotics-application-solution-guide?hsLang=en) WEBINAR [Explore our webinar for a deep understanding of how Hirose connectors facilitate advancements in surgical robotics.](https://info.hirose.com/webinar-surgical-robotics?hsLang=en) EBOOK [Uncover the critical role of Hirose's innovative connectors in modern medical and surgical robotic technologies.](https://info.hirose.com/surgical-robotics-ebook?hsLang=en) **ABOUT HIROSE** [Our Company](https://www.hirose.com/corporate/en/about/message/) [Investor Relations](https://www.hirose.com/corporate/en/ir/) [CSR](https://www.hirose.com/corporate/en/csr/message/)   **RESOURCES** [Connector Selector](https://hirose.icata.net/iportal/CatalogViewInterfaceStartUpAction.do?method=startUp&mode=PAGE&volumeID=HRE00001&catalogId=3173360000&pageGroupId=&designID=HRED002&catalogCategoryId=&designConfirmFlg=) [Categories](https://www.hirose.com/product/category) [Applications](https://www.hirose.com/en/product/industry)   **CUSTOMER SUPPORT** [Partners](https://www.hirose.com/corporate/en/about/partner/) [Locations](https://www.hirose.com/corporate/en/about/global_network/) [Contact Us](https://info.hirose.com/contact?hsLang=en) © 2026 Hirose Electric Co., LTD. Corporation. All rights reserved. [Privacy Policy](https://www.hirose.com/corporate/en/terms/privacy/en/) | [Terms of Use](https://www.hirose.com/corporate/en/terms/en/) | [Membership Agreement](https://www.hirose.com/corporate/en/terms/membership/en/) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/linkedin-in-brands-solid.svg)](https://www.linkedin.com/company/hirose-electric-americas/) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/youtube-brands-solid.svg)](https://www.youtube.com/@hiroseelectricgroup) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/facebook-f-brands-solid.svg)](https://www.facebook.com/hiroseelectric/) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/instagram-brands-solid.svg)](https://www.instagram.com/hiroseelectricamericas/) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/linkedin-in-brands-solid.svg)](https://www.linkedin.com/company/hirose-electric-americas/) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/youtube-brands-solid.svg)](https://www.youtube.com/@hiroseelectricgroup) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/facebook-f-brands-solid.svg)](https://www.facebook.com/hiroseelectric/) [![](https://info.hirose.com/hubfs/raw_assets/public/Modules/assets/instagram-brands-solid.svg)](https://www.instagram.com/hiroseelectricamericas/) - SAMPLE REQUEST - CONTACT US ### Contact Us ### Request a Sample