DELL C5518QT, 139.7 cm (55"), 3840 x 2160 pixels, 4K Ultra HD, LED, 8 ms, Black DELL C5518QT. Display diagonal: 139.7 cm (55"), Display resolution: 3840 x 2160 pixels, HD type: 4K Ultra HD, Display technology: LED, Response time: 8 ms, Viewing angle, horizontal: 178°, Viewing angle, vertical: 178°. Built-in speaker(s). Built-in USB hub, USB hub version: 3.2 Gen 1 (3.1 Gen 1). VESA mounting. Product colour: Black