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 AOC U27B3AF/75, 68.6 cm (27"), 3840 x 2160 pixels, 4 ms, Black AOC U27B3AF/75. Display diagonal: 68.6 cm (27"), Display resolution: 3840 x 2160 pixels, Response time: 4 ms, Native aspect ratio: 16:9, Viewing angle, horizontal: 178°, Viewing angle, vertical: 178°. Built-in speaker(s). VESA mounting, Height adjustment. Product colour: Black