It is easy to know who is carrying the spy phone and monitor the person by simply calling on it through a special spy phone number, which has been fed into the spy phone. As soon as the spy phone receives a call from this special number, it answers the call automatically without ringing. Even the display remains unchanged as if no activity is taking is place. This device allows the user to discreetly monitor the conversations taking place through the spy phone's calls and text messages. Otherwise, it acts like an ordinary mobile phone and receives and makes calls. Endoacustica is capable of modifying Nokia, Siemens and Panasonic mobile phone series into spy phones.

No other spy telephone has such exceptional features. This phone can be used with any SIM card in any country. It can also be used as an Infinity Transmitter. It allows the user to listen to room conversations even when the user is at a distance.