F means that the product is rated in its category in terms of energy efficiency. The Energy Labeling system is based on EU Regulation 2017/1369/EU. F Grundig 75 GUB 6400, 75", 3840 x 2160 pixels, 4K Ultra HD, LED, Smart TV, Black Grundig 75 GUB 6400. Display diagonal: 75", Display resolution: 3840 x 2160 pixels, HD type: 4K Ultra HD, Display technology: LED, Screen shape: Flat. Smart TV. Motion interpolation technology: VPI (Video Perfection Index) 1200, Native aspect ratio: 16:9. Digital signal format system: DVB-C, DVB-S2, DVB-T2, DVB-T2 HD. Ethernet LAN. Product color: Black