Features: Dual-way intercommunication Dual-way audio record Anti-interruption and noise Slim fit design of the speaker Streamline design: The main unit has an aluminum alloy shell, and the extension has a built-in speaker. This system has a simple connection for DIY operation. High quality: This system has a top-quality speaker and high-sensitive microphone. Especial the metal tube microphone is a deal for the counter and the dual-way inter-communication. Good performance: The voice from this system is clear, and natural. There is a switch only for volume control. Advanced technique: For this system, we adopter the advanced microcomputer from the U.S.A. Definite instruction: The indicating lamp shows the track's working status. The simple operation I: Easy for dual-way intercommunication without pressing a button. Simple operation II: This system haw two knobs to adjust the inside and outside volume. When the indicating lamp for audio turns green, the intercommunication could begin. Simple operation III: You could record the voice through record jack. Best Choice: It suitable for the Bank, Securities Firm, Hospital, Station where the security glazing is installed. Specification: Type: Counter Intercom Interphone Material: Plastic + Aluminum alloy Input Voltage: 100-240V Plug: US, EU Quantity: 1 Set Package includes: 1 x host 1 x voice machine 1 x DC12V power supply 1 x double-sided tape 1 x line card