BNC for the RF and M6 BRASS wing nuts.
Reusable cable ties.
Inside the boxes (2" x 1" x 1/2" deep) connections are using solid wire that has been wound about a screw driver so it is sort of like a little spring, so if for whatever reason the connection goes loose the connection will still work.
As asked.... the vertical wire will have am M6 ring terminal soldered and crimped on on end that goes on one M6 and it is secured in place between the washers and the butterfly nut and the other end goes up the pole or whatever you are using to support it, the radials connect to the other M6, either bare wires just wound about the M6 bolt or M6 ring terminals. When they are attached to a pole I know which is which so have not labelled them but I might.
The boxes do have enough space for a T80 toroid balun to just fit inside but I have not done this. Nothing stopping you adding one outside or feeding differently.