Testo 0590 0013 - Measuring Cable Extensions (Straight Plug), 1 Set The cables supplied with the measuring instrument are not always the best solution. Depending on the application, a measuring cable extension is the best choice. Because you can make a direct connection between the measuring instrument and for instance a banana jack, without needing to use cumbersome crocodile clips. The same applies for example to test sockets, which are often present on boards. The measuring cable extension can also be used for crocodile clips, such as the Testo safety crocodile clips (0590 0008), which means there are universal application options.