Heuer Instruments - Telecom Test Equipment
The product line also include Voice Frequency Testing, Wideband, TIMS, Audio/Sound Broadcasting Testing and Multi Function Line Testers like the one below.

The LT51 Line Tester is a portable handheld battery powered instrument for Data, DSL, Telephone, Voice Copper Line testing. It combines the features of several pieces of test equipment such as a Level Meter / Spectrum Analyser, Distortion Analyser, Oscillator, Handheld DMM and TDR in the one small lightweight package.
H Heuer Instruments Pty Ltd
766 Pennant Hills Road, Carlingford NSW 2118, Australia
Updated Aug 2013