WARNING to potential buyers: The “4K” display in this laptop is fake!
The display uses the RG/BW Pentile matrix to cheat the ability to advertise 4K UHD 3840x2160, without actually providing the full detail of the resolution. If you do the math, it actually has less chromatic detail than the 3K 2880x1620 in the older ASUS UX51vz.
The Inspiron 4K someone else linked has this same problem. If you want a 100% honest true 4K 15.6" display with a NVIDIA 960M at a close enough price point, you pretty much have to buy the Lenovo Y700 4K: https://www.newegg.com/Product/Product.aspx?Item=N82E16834332105 ($1099, a great option but also your only one)