BenQ's T420 Interactive Flat Panel combines the power of touch technology and multimedia connectivity to maximize the experience of all types of users from the boardroom to the classroom. The Optical Touch panel always gives responsive feedback with accurate positioning. You can touch the screen to pan, zoom and scroll images with two fingers through our Nextwindow technology on Windows 7 and Windows 8. This eliminates the need for a mouse or keyboard, so you can operate education software or presentations with your fingers like using a tablet. BenQ T420 not only saves you money with superior energy efficiency but also offers the best display performance. The PID (Public Information Display) panel is made for extended daily use while keeping uniform brightness, high reliability, and superior durability. Screens displaying the same image for an extended period of time could exhibit an “Image Retention” problem. Fortunately BenQ has an answer for it: the "Anti-Image Retention" feature randomly rotates each pixel on the screen with effects barely noticeable to the human eye. This system actively protects the display to make its service life even longer. The PIP (Picture-in-Picture) function enables BenQ displays to show images from two different video sources simultaneously, so you can take advantage of this feature to monitor one source while watching another, or use the embedded video to enrich your presentations. (Composite and S-video sources not supported). BenQ displays also have ambient light sensors that can automatically adjust brightness according to ambient light levels to make viewing more comfortable. BenQ displays are made to last and save energy. Internal temperature sensors continuously register the thermal status of the displays and make appropriate adjustments to the system for better reliability and power efficiency over the entire lifecycle of the product.