CTR-TEL not only alerts you when your telephone is being tapped, it also automatically disrupts the telephone tap by emitting a load tone and disrupting the monitoring station or tapping device. The frequency detection is 1 MHz - 6 GHz and is not polarity sensitive, so "Tip and Ring" can have any position on the line.
Unlike other models which require a voltage drop to trigger a monitoring station, or an increase in line voltage to disrupt a recording device, CTR-TEL is line powered at a max of 1mW and always on guard.
CTR-TEL can withstand line voltage up to 110 volts and is therefore protected from those who place an electrical current on the telephone line to disable a telephone tap detector.
It is compatible with all types of phones, residential commercial, PBX, Fax and DSL.
CTR-TEL does not interfere with normal telephone services nor degrades it. It is recommended that CTR-TEL remain on the telephone line at all times to achieve its maximum goal.
Its easy to install modular feature allows it to be jacked in and jacked out at will.
CTR-TEL can be installed on a single telephone line disrupting its taping or on an extension on the same telephone line, or at the demarcation point from where all telephones on the specified telephone line cannot be tapped.