I needed a cheap docking station for my work, which was released by the second generation Lenovo ThinkPad X1 Yoga so that I could use a real keyboard and monitors in my home office. So far this has worked great. With a single USB-C connection to the laptop, it charges the battery and drives two 27-inch Acer G277HL Full HD (1920 x 1080) monitors via standard HDMI cables. As a bonus, it also charges my iPhone 8+ and supports wireless keyboard and mouse. Amazing - all over a single USB-C connection and at a fraction of the cost of a factory dock. Can't comment on 4K monitor compatibility as I don't have one.
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