5. Function Key Control (while video talking) ES Re DISPLAY : Press DISPLAY key to switch the screen mode and size of the video displayed on your LCD screen. 1. Twin screen mode 2. Full local screen mode 3, Full remote screen mode 4. Zoom-out remote screen mode MUTE : Press MUTE key to prevent the remote side from hearing your voice. PRIVACY : Press PRIVACY key to block your outgoing image to the remote side.