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 Alienware AW2521HFA, 24.5", 1920 x 1080 pixels, Full HD, LCD, 1 ms, Black Alienware AW2521HFA. Display diagonal: 24.5", Display resolution: 1920 x 1080 pixels, HD type: Full HD, Display technology: LCD, Response time: 1 ms, Native aspect ratio: 16:9, Viewing angle, horizontal: 178°, Viewing angle, vertical: 178°. Built-in USB hub, USB hub version: 2.0 / 3.2 Gen 1 (3.1 Gen 1). VESA mounting, Height adjustment. Product color: Black https://www.pcmag.com/picks/best-gaming-monitors-for-xbox Maybe you just got your first Xbox, the Xbox Series X this holiday season. Or maybe you're still playing on one of the later Xbox One consoles. Either way, are you getting the most out of your console-gaming experience by playing your games on your TV? Wh... https://www.pcmag.com/reviews/alienware-25-gaming-monitor-aw2521hfl Speed is key for gaming monitors, and the Alienware 25 is among the fastest we've seen yet, in terms of input lag and refresh rate. This 25-inch 1080p monitor boasts an input-lag measure of just a millisecond at its peak refresh, which helps justify its $... Superfast 1-millisecond input lag, Lofty 240Hz refresh rate, Attractive, futuristic design complements other Alienware hardware well, So-so color performance, G-Sync Compatible adaptive sync exhibits choppy motion at times The 240Hz Alienware 25 is a reasonably priced 25-inch 1080p gaming monitor with a fairly bright picture and extremely low input lag. It will thrill twitchy esports hounds, but its colors don't impress...