Viking' s TG-1 privacy device prevents your phone call or fax and modem transmissions from being interrupted if someone accidentally picks up another extension. The TG-1 can also secure against internal eavesdropping by any other extension equipped with a Viking Teleguard device. The TG-1 provides single line Teleguard protection ideal for punch down or terminal block installation. The TG-1 protects the device that accesses the telephone line first by denying other Viking Teleguard equipped devices access to the line until the call in progress has been terminated. Incoming calls will ring all devices simultaneously, but the device that answers first denies any other Teleguard equipped device access.