Optoma HD37 1080p 3D DLP Home Theater Projector Screen Size Range: 66-inches from 8 feet; 99-inches from 12 feet Brightness: 2,600 ANSI Lumens Contrast Ratio: 20,000:1; Keystone Correction: Yes, Lens Shift: Yes Warranty: 1-Year Limited Parts and Labor, 90-Days on Lamp Inputs: Two HDMI (w/MHL), VGA-in, composite video, stereo audio-in, RCA stereo audio-in, stereo audio-out, 12V trigger, RS-232C, USB-A (power), mini-B Use the USB-Power to power an HDMI dongle, such as Google Chromecast or the Optoma HDCast Pro wireless HDMI device. It eliminates the hassle of running extra HDMI cables or power adapters for the wireless HDMI device.