Bright 4,000 lumens and 22,000:1 contrast ratio produces razor-sharp images PC-free USB image viewer and office document reader Wireless presentations and images with HDCast Pro (USB Wi-Fi adapter included) USB display screen mirroring with iOS and Android devices LAN display via Ethernet with Windows and Mac OS X Auto keystone and four corner correction for robust installation Spectacular 115" WXGA image from inches away Project large, 115-inch WXGA images from only inches away with the bright 4,000 lumens Optoma W340UST. Its 22,000:1 contrast ratio and ultra short throw ratio of 0.25 make it ideal for space-constrained environments, such as small classrooms, meeting rooms, house of worship and boardrooms. A PC-free image viewer and document reader display office documents, PDFs and images from USB storage devices. HDCast Pro connectivity provides wireless screen mirroring with Android, Mac OS and Windows devices. LAN display supports up to 4 simultaneous computers while USB display mirrors Android and iOS devices. Four corner geometric correction allows flexible installations while robust input options include HDMI, VGA and RJ-45 for connectivity to a wide range of devices.