How to open this "repack" reservoir

[BobbyBoyGaming]

I bought this "repack" 5.25 bay reservoir, but I need to know how to open this top fill port. I dont understand how it works. It looks like it needs some type of key, but my reservoir did not come with any key. How do I fillt his thing up?!

 

[BobbyBoyGaming]

I also have a separate question,
Do the alphacool radiators have to be rinsed with pure water before use (when brand new)? or are they clean already?

 

[Luckystricker]

Hi @BobbyBoyGaming

You can open the screw with a small coin or a flathead screwdriver. Normally, if your set is the V.4, some kind of key would be included. Looks like a T, black plastic and with the ACool lettering.
Regardless of the manufacturer, you should always rinse all components with distilled water before installing them, especially the radiators properly. Since these can contain more residues due to the soldering.

Best Regards