... the4 frames , not so easy to maintain , etc .,Specification : MultiTouch Interactive Whiteboard Touch Technology:Optical ImagingInput Method:touching&writing by finger or ... fingers/normal pens/any opaque objects operating together under WIN72.Strong hardware and perfect structure design, one-time installation, no drift ... )1808×1400HT-97102inch2099.3×132097.6inch(16:10)2160×1400 Interactive whiteboard