Lenovo ThinkPad Ethernet Extension Adapter Gen 2
Prices in SGD, excluding 9% GST.
PRODUCT DESCRIPTION
ThinkPad Ethernet Extension Adapter Gen 2 (4X90Q84427) - Singapore Local Warranty
Full-Size RJ-45 for Slim ThinkPads
The ThinkPad Ethernet Extension Adapter Gen 2 plugs into the Ethernet extension connector (mini RJ-45) on selected slim ThinkPad notebooks and gives you a standard RJ-45 port for wired networking.
Gigabit Through the Laptop's Own Controller
The adapter uses the notebook's built-in Intel Gigabit Ethernet controller, so the connection runs at Gigabit Ethernet speed with no extra driver — Lenovo describes it as driver-free, plug and use.
PXE and Remote Management
Supports PXE boot and remote control, and on supported ThinkPad models Lenovo lists Wake-on-LAN, making it a fit for IT imaging and managed fleets.
Tiny 80 mm Cable
Just 80 mm long in a small form factor, it stays out of the way on the desk and in the bag.
ThinkPad Ethernet Extension Adapter Gen 2 Datasheet — Technical Specifications
General
| Product | ThinkPad Ethernet Extension Adapter Gen 2 |
| Part Number | 4X90Q84427 |
| Product Type | Cable adapter |
| Manufacturer Warranty | Not published by Lenovo |
| Local Warranty (Singapore) | Included with every SourceIT purchase, with GST invoice |
Network
| Laptop Connector | ThinkPad Ethernet extension connector (mini RJ-45) |
| Network Port | 1 x RJ-45 |
| Speed | Gigabit Ethernet, provided by the ThinkPad's onboard Intel Ethernet controller |
| PXE / Remote Control | Supported |
| Wake-on-LAN | Supported on ThinkPad models whose Lenovo specifications list it |
| Driver | Driver-free, plug and use |
Physical
| Cable Length | 80 mm |
| Form Factor | Small form factor |
Compatibility & Fit
Fits Only ThinkPads with an Ethernet Extension Connector
This is not a USB adapter. It works only on ThinkPad models that have the Ethernet extension connector and whose Lenovo specifications name the ThinkPad Ethernet Extension Adapter Gen 2. Lenovo's specifications list it for, among others: ThinkPad X1 Carbon 6th Gen, 7th Gen and Gen 8, X1 Yoga Gen 5, T490s, X390, T14s Gen 1 and X13 Gen 1, and Ethernet-equipped configurations of T14s Gen 2 (Intel) and X13 Gen 2 (Intel).
Check for the Ethernet Icon
On T14s Gen 2 (Intel) and X13 Gen 2 (Intel), Lenovo notes some configurations have no onboard Ethernet: if the connector has no Ethernet icon beside it, it does not support Ethernet. Those models should use a USB-C Ethernet adapter instead.
Not for Newer or Non-Listed Models
Models without the connector — for example ThinkPad X1 Carbon Gen 9, which Lenovo pairs with a USB-C to Ethernet adapter — cannot use this adapter. The Gen 2 adapter is also a different part from the original ThinkPad Ethernet Extension Adapter used on earlier ThinkPads. Confirm your model in Lenovo SmartFind before ordering.
USB Alternatives
For any laptop with USB-C, the Lenovo USB-C to 2.5G Ethernet Adapter (4X91H17795) is a universal option; for USB-A ports, the ThinkPad USB 3.0 to Ethernet Adapter (4X90S91830).
Package Contents & Lenovo Ordering Information
In the box:
- ThinkPad Ethernet Extension Adapter Gen 2
- Documentation
Lenovo Cables & Adapters Ordering Information
| 4X90R61022 | Lenovo USB-C to HDMI 2.0b Adapter |
| 4X90Q93303 | Lenovo USB-C to DisplayPort Adapter |
| 4X90M42956 | Lenovo USB-C to VGA Adapter |
| 4X90J31021 | Lenovo USB 3.0 to DisplayPort Adapter |
| 4X90R61023 | Lenovo DisplayPort to HDMI 2.0b Adapter |
| 4X90Q93976 | ThinkStation Mini DP to HDMI Adapter |
| 4X91H17795 | Lenovo USB-C to 2.5G Ethernet Adapter |
| 4X90S91830 | ThinkPad USB 3.0 to Ethernet Adapter |
| 4X90Q84427 (this listing) | ThinkPad Ethernet Extension Adapter Gen 2 |
| 4X90Q59481 | Lenovo USB-C to USB-A Adapter |
| 4X90U45346 | Lenovo USB-C to Slim-tip Cable Adapter |
Datasheet & Downloads
- Lenovo product page — 4X90Q84427
- Lenovo PSREF — ThinkPad X1 Carbon Gen 8 specifications (lists the Gen 2 adapter)
- Lenovo PSREF — ThinkPad T14s Gen 2 Intel specifications
- Lenovo Accessories SmartFind — 4X90Q84427
Check your ThinkPad's Lenovo PSREF specification or Lenovo SmartFind to confirm it lists the Ethernet Extension Adapter Gen 2 before ordering.
Frequently Asked Questions — ThinkPad Ethernet Extension Adapter Gen 2
Will this work with my laptop's USB port?
No. It only plugs into the ThinkPad Ethernet extension connector (mini RJ-45) found on selected ThinkPad models.
Which ThinkPads does it fit?
Models whose Lenovo specifications list the Gen 2 adapter, including X1 Carbon 6th Gen, 7th Gen and Gen 8, X1 Yoga Gen 5, T490s, X390, T14s Gen 1, X13 Gen 1, and Ethernet-equipped T14s Gen 2 (Intel) and X13 Gen 2 (Intel). Check Lenovo SmartFind for your exact model.
How fast is the connection?
Gigabit Ethernet, provided by the ThinkPad's onboard Intel Ethernet controller.
Does it need a driver?
No. Lenovo describes it as driver-free, plug and use.
Does it support PXE boot?
Yes. Lenovo lists PXE and remote control support.
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