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 Sharp 4T-C55FL1KL2AB, 139.7 cm (55"), 3840 x 2160 pixels, LED, Smart TV, Wi-Fi, Black Sharp 4T-C55FL1KL2AB. Display diagonal: 139.7 cm (55"), Display resolution: 3840 x 2160 pixels, HD type: 4K Ultra HD, Display technology: LED, Screen shape: Flat, LED backlighting type: Edge-Lit LED. Smart TV. Contrast ratio (typical): 1000000:1, Native aspect ratio: 16:9. Digital signal format system: DVB-C, DVB-S, DVB-S2, DVB-T, DVB-T2. Wi-Fi, Ethernet LAN. Product colour: Black