The XT500 is an extension cable which lets you connect a 500 series module to your lunchbox while keeping it outside for easy setting or maintenance.
Test pins on every connector contacts make measurements easy.
You bring the solder (use good quality solder, 1mm diameter max) and the Lunchbox.
The XT500 kit is a very easy build.
If you prefer not to DIY, choose an Assembled product.It comes fully assembled, ready to use.