You can use the conversation between the inside and outside of the window for the customers' evaluation of the salespersons, and for the supervisor's evaluation of each windows.
1. Usage: the bank staff use the master station to talk with guests. and the guests use the substation can talk with bank staff as well. 
2. Installation:the master station is installed in the working place and the sub station out of the working room. Just one wire connection between the master station and substation. 
3. Applicaton: bank, restaurant ,stock office, hospital, post office, Box office, Ferr charge station Where guard glass again theft is installed 

Functions and Features:
1.Knob Voice Adjustment,can adjust voice by worker freely. 
and  Signals can transmission simultaneously from different directions;so window speaker system can automatic recognize and process the speech signals; much clear sound; less statics.
2.High-sensitive Microphone, Loud and Clear Voice; This system adopt the advanced microcomputer. It has good speaker and high-sensitive microphone. Especial the 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.
3.Easy to use; just need to connect with power adapter and outside speaker to the main station; the microphone cable is flexible.
4. Dual-way Audio Record: Inside and outside the two-way voice signal output(recording by the bank teller), a stereo jack output mode can prevent voice recording function controlled by the power switch and the function buttons.
5. Application: Anti-interference and noise-free function.It suitable for the Bank window, Ticket offices,Hospital window, Post office window, Securities window, Embassy visa office, Securities Company , Hospital, Station where the security glazing is installed.

Specification :
1. Two-way voice intercom communications technology, automatic identification of processing speech signals during a call, does not require any action;
2. With power on /off and volume knob can control volume by worker 
3. Dual-way audio record output; Dedicated anti-side tone processing chip with aoto-mute function
4. Has special side tone processing chip and the movement noise function can effectively improve the noise
5. The voice from this system is clear and natural; Has top-quality speaker and high-sensitive microphone. Especially the metal tube microphone is deal for the counter and the dual-way intercommunication
6. Main base Dimension:153*78*40mm   
    Substation dimension: 68*20mm
7. material : Aluminium + plastic 

Technical Parameters:
working voltage: DC12V/0.5A  
input voltage: AC 110-240V
work power : 2W,100Hz-15Khz 
Inside microphone : -48db 20Hz-20Khz 
Outside mirophone: -48db 20Hz-16Khz 
cable length : 1.8M 

Packaging List:
1 x Dual-way counter interphone
1 x External speaker
1 x Charger
4 x Adhesive
1 x English User Manual