1,bluetooth transmitter 2,handheld type or usb headset 3,page turner:page up/down 4,laser pointer,MP3 play 5,LCD diplay ... use.5. LCD display power supply,low battery,signal link,volume and so on.6. Remote electronic laser pointer,page turner, USB upgrading ... are combined in this all-in-one unit, for revolutionary, cable-free convenience.More specifications:Transmitter(Holding) Frequency Scope: 2.4 ...