the United States, the Philippines and so on.     Voice Communication Dual-way intercommunication Signals can transmission simultaneously from different directions;so window speaker system can automatic recognize and process the speech signals; much clear sound; less statics.     High-sensitive Microphone, Loud and Clear Voice This system adopt the advanced microcomputer from U.S.A. It has top-quality speaker and high-sensitive microphone. Especial the metal tube microphone is deal for the counter and the dual-way inter-communication.The voice from this system is clear,and natural, anti-interruption and noise.There is a switch only for the volume control.     Streamline Design Windows Speakers The main unit has aluminum alloy shell, and the extension has built-in speaker.This system has simple connection for DIY operation.     Simple OperationEasy for dual-way intercommunication without pressing button. This window speaker system has two knobs to adjust the inside and outside volume. When the indicating lamp for audio turns green,the intercommunication could begin. You could record the voice through record jack. It is very user-friendly.     Wildly Application It suitable for the Bank window, Ticket offices, window, Post office window, Securities window, Embassy visa office, Securities Company , , Station where the security glazing is installed.     Working voltage: DC9V/0.5A     Input voltage:AC 110-240V     Main sound (sub sound): 2W, 100Hz-15KHz     Inside microphone: 48db 20Hz-20KHz     Outside microphone: 48db 20Hz-16KHz     Colour:Silver     Material:metal     Size:Cable Length :1.6m/5.25ft     Main box size :158x87x46(335)mm / 6.2 inch x3.4 inch x1.8 inch (13.2inch)     Sub-box size :91x77x23mm / 3.6inch x3 inch x0.9 inch     Package Contents:     1x Dual Way Counter Intercom interphone     1x Power Adaptor     1x User Manual     Only the above package content, other products are not included.     Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.