This unit prevents eavesdropping or dialling across calls when an extension line is fitted.
When one of the phones is used, the unit operates on a 'first come first served' basis, blocking interference from other phones (modems, etc.) on the line and indicating this through the LED's.
It is easy to install and ideal for use anywhere an extension line is fitted.
Complies to Oftel NS/G/23/L/100005 regulations.