Bank teller window intercom my-a09 adds new voice

About Product:2. Ultra-thin external extension, small size, beautiful appearance, the external microphone has been placed in the extension. The internal and external only one line, simple installation. 3. The host has its own microphone head. \"And it can directly talk to the extension without using the built-in microphone. 4. The system playback is realistic and clear. Independently independently adjusted and external volume can be switched on. 5, microcomputer processing circuit, with static noise function, and completely solve the echo, Noise problem. 6. There is a recording jack, which can output internal and external dual channel sound signals (with bank teller recording).