Chauvin Arnoux CT 51 [P06237901] Multimetrix Networks, Telecom Cable Tester.  The Multimetrix CT 51 is a simple cable tester for the cable types RJ-45, RJ-11, USB, 1394 and BNC:

• RJ-45 for testing LAN and INTERNET 10BASE-T cables, EIA/TIA-568/568B, AT&T268A, Token Ring and other cabling systems with RJ-45 connectors
• RJ-11 for testing telephone and phonenet cables and others Cabling systems with RJ-11 plug contacts
• IEEE 1394 for testing cables with IEEE 1394 Connectors
• USB B for testing USB connection cables and other cabling systems With USB plugs
• BNC for testing terminal connection cables ETHERNET 10BASE-2/10BASE-5

Operation is done via only one button. With the removable transmitter module, the measurement can be done by only one person. Measurements can be made on cables up to 180 m long. The cable tester also offers continuity testing, open circuit testing and short circuits.