D 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. D Lenovo ThinkCentre Tiny-In-One 24 Gen 5, 23.8", 1920 x 1080 pixels, Full HD, LED, 6 ms, Black Lenovo ThinkCentre Tiny-In-One 24 Gen 5. Display diagonal: 23.8", Display resolution: 1920 x 1080 pixels, HD type: Full HD, Display technology: LED, Response time: 6 ms, Native aspect ratio: 16:9, Viewing angle, horizontal: 178°, Viewing angle, vertical: 178°. Built-in USB hub. VESA mounting, Height adjustment. Product color: Black