How does this outlet box work? How to split a cable?

[James TF]

I want to install this set-up on my terrace (the plug goes into a dry closet). E.g the outlets are permanently installed, but the plug for them I'll just disconnect when not in use.

The wire is 1,5m2, and will only be used for phone charges and lightning so having both outlets on one wire is not a problem.

Questions:

1. How should I split the wire like shown in the diagram? I'm sure they sell some thing designed for this - for outdoor use?
2. How am I supposed to connect the outlet shown in the photo? I guess one wire goes to number 1, the other to number 3. But I don't understand the ground situation here? What is the purpose of number 5? It's not connected to anything? Does the neutral wire connect under the screw in number 6?

 

[westward10]

5 is probably a loop terminal and can be ignored. Earth goes to 6, blue and brown go to 1/2 and 3/4 not sure which way if polarity must be maintained but they are not marked from what I can see with L and N.