C2G 54292 USB Powered 4K 2-Port Mini DisplayPort to HDMI MST Hub Monitor Splitter, Black

This thing works fine, but you MUST use the power cord that comes with the device, which plugs into the Micro-B slot on the back of the adapter. My old adapter didn't require power, so I ignored this one initially. When I tried to use this device without the power cord plugged in, nothing worked. As soon as I recognized my mistake and applied the power cord, all worked perfectly.

Worked great at the start for my Surface laptop 2. Now, 6 weeks later, it is constantly flickering on and off. Past return window. So disappointed in this. Save your money. Update: Contacted Customer Serivce who sent a new one. That was great service. Unfortunately, now the new one has stopped working after about 2 months. AVOID this product!

The Surface Dock is far more expensive and simply does not work. This is simple, clean and functions perfectly.

I needed this to connect two hdmi monitors to a single mini display port. This product works exactly as it should, however, you need external power. The box comes with the cable you need but you’ll need to use a spare iPhone power brick or whatever to power the adapter. It’s not a big deal but wish the description was clearer. Other than that minor item, the adapter works perfectly. No flickering, no screen distortions, no lag.

With all the reviews I was a bit hesitant but once received plugged, reboot it did its job. You can extend/duplicate displays without any issues. I have a surface pro 6 with one Dell “32 LED Curved QHD (left) and an HP 32” IPS LED FHD (right) monitors and it looks good and what I need it for. I had to figure out how to plug my wireless mouse since you have to plug the power cable and the mini port in order to work. So I just used the charger’s USB port and plugged it there and kept the usb for the mouse (see pics). Better than paying $250 for a docking station!

The splitter works perfectly on Windows, it does not work *at all* on any Mac OS. I have a laptop that boots to Mac and Windows, the splitter works on Windows, does not work on Mac. I specifically asked their support if this device would work on Mac, they said yes. Clearly they've never tested the device on Mac. This is a duplicator when used on Mac (which you can find for ~$20 bucks) but does work on Windows. Only reason I'm not rating it 1 star.

It’s very hard to keep the pictures on my monitors. The pictures now blink too much to be practical. It did last a year but should probably last longer for its price

I bought this product to add a second monitor to my older MacAir laptop. I am only using one of the HDMI outputs to run a single second monitor, and I do not think my system can extend to a third monitor. So, I do not know if it is splitting the video from the ThunderBolt 2 port to both HDMI outputs, or if it can run the two HDMI ports independently. But, this setup works well for me.