The ThinkPad USB 3.0 Ethernet (4X90E51405) adapter enables Ethernet on systems which do not have Ethernet RJ-45 connector through USB port on the system. The ThinkPad USB 3.0 Ethernet adapter not only provides high speed Gigabit Ethernet solution via USB 3.0 port, but also enables boot over the LAN on selected ThinkPad systems.

Connect it with your Ultrabook or Tablet to your corporate VPN at the office or go online in a hotel suite. The adapter’s small form factor allows a convenient fit into any computer case or bag to travel, so you can easily take it with you anywhere.


- Full size RJ45 connector; LEDs on connector to indicate connection status
- Two LEDs on RJ45 port for power and data transfer indication. Green for power and Yellow for activity.
- Booting from LAN and loading image from remote server both on legacy BIOS and UEFI BIOS system
- QoS (Quality of Service) tagged packets and duplicate address detection
- Doesn’t support POE (Power over Ethernet)
- Giga bit speed when running on USB3.0 environment
- 100M/10M adapt when running on USB2.0 environment
- Full Duplex flow control (IEEE 802.3x)
- Compliant with IEEE 802.3 and IEEE 802.3u
- IEEE 802.3az Giga bit Ethernet requirement