Lenovo 4X90F84315 ThinkPad Ethernet Extension Cable, Black

This adapter works great with the Lenovo X380 Yoga. It connects at 1 Gbps without issue. It was ready to go out of the box, with Windows 10, without any extra drivers. There seems to be a lot of confusion about the type of port that is needed for this dongle. I don't know if it's proprietary to Lenovo, but I've never seen this type of connector before. The owners manual calls this "Mini Ethernet connector" Note: This will not fit any USB port (including USB-C, there's a different adapter for that). This will not fit a mini-display port, nor will it fit a micro HDMI port (even though they are about the same size). The port this will fit has the same logo you see in the picture, which is actually the IT symbol for LAN (three squares connected to a horizontal line)

This dongle does the job of connecting my laptop to my network through a wired connection. It fits my Thinkpad perfectly. The strange part being I had to get this part through Amazon. When I tried to order it through Lenovo, they sent me the wrong part, which I returned. They were never able to supply the correct part. I ended up doing a Google to find the correct part number and then found it on Amazon.

I was using ThinkPad dock but got horrible network performance (I had the original cable that came with the device but wanted to leave it at home and use the dock at work) Got this cable and stopped using the dock network and network performance improved dramatically, still next time I think I'll look for device with regular RJ-45 network socket and not propriety one..

This review is for the "Lenovo 4X90F84315 ThinkPad Ethernet Extension Cable, Black". Out of all the Ethernet adapter cable dongles that are supposed to work with ThinkPad laptops, I chose this one to order. Unfortunately it did not fit my ThinkPad X1 Carbon 7th Gen computer. The connector on the laptop end is incorrect. The adapter cable, though, seems to be well constructed and would be a great cable for those laptops for which it is designed.

So I recently got Fios Gigabit and I was trying to test it on a bunch of other USB (both A&C) 3.0 Ethernet adapters. None of my laptops were ever able to show true gigabit speeds with those adapters. So I suspected it was the either the NIC or the drivers causing the reduced speeds (450 Mbps) since my WiFi (Synology) put out 550~600 Mbps on AC wifi, but I couldn't be sure until I got this adapter. I was so happy to see that my laptop was able to pull almost 940 Mbps with Ookla (speedtest.net) and 1 Gbps on Fast.com. A side note: I've noticed a bunch of negative reviews about this product from people trying to plug it into various ports it's not intended for. I attached the icon the port has as well as a picture of the port. I hope it helps clear up the confusion. I used it on my Lenovo X1 Extreme Gen 1.

Got this for a Lenovo Yoga X1 machine, and was a bit worried being that not all of these adapters are compatible with all Lenovo machines having this mini-ethernet port. But this particular model works for my Yoga X1. I was provided a different adapter that looks exactly the same, and that one did NOT work, so the models for these are definitely important.

Bought myself a new laptop, and had to pick this up since this is the only network port on it. I do have a USB connector for a network cable, but it didn’t work on this laptop. This is what I needed. It is a very distinct looking plug, and it’s not USB-C. If you have a weird-looking spot with the network symbol on it (one side is slightly rounded, rest is straight, and is about the size of USB-C), this is what you need. If not, just get a USB adapter - it’s cheaper anyway.

Wandered here to look up the part no. of this dongle. Despite what *some* reviewer(s) are saying, this dongle does provide gigabit speed (just tested/confirmed). I usually work and connect through a thunderbolt 3 dock, so this dongle rarely gets used. Needed to quick check the quality of a new cat8 cable: 1Gbps google fiber > cat 8 + dongle > X1 Yoga 3rd gen == 530-550Mbps down, 400 - 430 up consistently, in a home with multiple (min 12 devices connected simul) AND while my partner was on a mult-person zoom meeting over wifi. I just wish it were multi-gig-capable.

Parfait pour Thinkpad L390 et L380, permet de se connecter avec un câble RJ45, sur le port spécifique de ces machines.

Funziona bene.

Muy conforme con el producto

Works well, allows wake-on-lan, and saves a USB port. Much better than using a USB network adapter.

Works like it's supposed to. I like the light indicators and how flexible and sturdy the cable is.