A:Answer For 4K models, TCL Offers the following series: 4, 5, 6, and 8. Each series builds on each other. All of these series are 4K UHD, have HDR support, and have a Roku operating system. The 5-Series, 6-Series, and 8-Series additionally have Dolby Vision Support as well as a wide color gamut, auto-game mode, an edge-to-edge glass display, etc. The 6-Series and the 8-Series both feature Quantum Dot Technology (QLED). The 6-Series features CCZ technology while the 8-Series has Quantum Contrast. You can also visit www.tclusa.com/products/home-theater/8-series and scroll down to "Compare All Models" to see all models compared. Hope this helps! Thank you, TCL Customer Support