... transmission , energy saving; ISO 9001 , CE, ROHS ,FCC, International Standard Product,etc3 Built-in Stereo SpeakerIt built in stereo ... mask, cover, timer, etc;4)Multi media play: support import or export Word, PPT, excel files, video, audio play; quick ... better use of network resource, increasing interesting of the class or meeting;6) Remote & Interactive Communicate : Network sketchpad, network ...