Zenith HDV420 HDTV Digital Video Tuner / Receiver Performs over-air, all-format HDTV reception: 1080i, 720p, 480p, 480i, and native output Uses Zenith's 4th-generation VSB technology for improved terrestrial/cable reception and noise immunity Selectable output format allows configuration on different displays in both 4:3 and 16:9 formats Dolby Digital 5.1-channel output for immersive surround sound when used with a compatible AV receiver and multichannel speaker system User-friendly graphical user interface, fast program search, digital closed-captioning