The new and elusive 17.3-inch 4K UHD 120 Hz AU Optronics display can only be found exclusively on the Razer Blade Pro 17 at the moment. We don't know when it will begin shipping on competing laptops, but we do know that it offers the best 4K UHD gaming experience on a 17.3-inch laptop due to its significantly faster response times and refresh rates than any existing 4K UHD IPS panel and 4K UHD OLED panel, respectively.
https://www.notebookcheck.net/Razer-Blade-Pro-17-is-the-first-laptop-to-do-4K-UHD-gaming-right-Here-s-why.440568.0.html