Usable with any SIM card in any country, this spy phone appears to be a normal phone. It shows its true characteristics when it receives a call from a previously programmed spy phone number. On getting a call from this special number, it does not ring, nor do its lights come on and its display appears motionless. However, the call is answered automatically. So, through the special spy number, user can easily monitor the person carrying the spy phone. Endoacustica can modify Nokia, Siemens and Panasonic mobile phone series and convert them into spy phones.

Moreover, this spy phone can also double up as an Infinity Transmitter. This allows the user to listen to room conversations from a distance.