This supplementary kit contains everything else you need to complete the project other than the Nutube, B1K PCB + JFETs, and chassis.
It’s an assortment of bits and pieces that joins the Nutube, B1K PCB + JFETs, and chassis together, turning the whole thing into a “full kit”.
The included “wall wart” style power adapter supports an input voltage of 90-264V and has a USA style plug. If you don’t live in the USA, you will need to obtain a suitable plug adapter.