Does wivitouch IR Dual multitouch frame has a glass or only a frame?

WiViTouch's IR dual-touch screen(two touch points): the size below 80'' have glass, the size over 80'' don't have a glass.

Two Reasons for over 80'' no glass:
* The size is too big, there is no glass suit for it.
* Too big size glass installed in the frame, it is easy be broken in shipping.