Lenovo 4X90F84315 original LAN-Adapter - Ethernet extension cable - sparepartworld.com
Amazon.com: Zahara Adapter Dongle Cable 4X90F84315 SC10A39882BB Replacement for Lenovo Thinkpad X1 Carbon (2nd Gen 3rd Gen )/X1 Extreme (2nd Gen )/ X380 Yoga/ThinkPad Yoga 370 Ethernet RJ45 Extension 04X6435 : Electronics
New Original For Lenovo ThinkPad X1 Carbon Ethernet Extension Cable Adapter RJ45 4X90F84315/04X6435 4X90Q84427/01YU0261 From Miyuefang, $48.92 | DHgate.Com