Audio Devices - GSM microphones

By using a SIM Card, this system allows you to listen while you dial a specific phone number (the one that was in use on the cell phone).

By using a SIM Card, this system allows you to listen while you dial a specific phone number (the one that was in use on the cell phone).

By using a SIM Card, this system allows you to listen while you dial a specific phone number (the one that was in use on the cell phone).

By using a SIM Card, this system allows you to listen while you dial a specific phone number (the one that was in use on the cell phone).

This system allows you to listen every call sent or received at any distance.