The KUPO 19 core test is very easy to use and can quickly diagnose lines. It is modified from PLS series 19-core plugs, has a built-in electronic chip testing circuit board, and is equipped with a 9V battery. It can be suitable for testing international standard 19-core extension cables. The two ends of the extension cord are connected to the male and female terminals of the tester respectively, and the normal wiring conditions of the six circuits can be tested in a few seconds.