Question about difference between fittings

[BobbyBoyGaming]

Hello I have mutiple fittings from alphacool for soft tubing (13/10mm) and some of them look nickel plated on the inside and the other ones are bare copper on the inside.
On the outside they look identical. Can somebody please tell me why they are different? Are they different quality/performance? or is it just a visual aesthetic?

 

[BobbyBoyGaming]

Here is a photo of what I am talking about. Everything appears to be the same. I think the internal diameters are identical. The only difference is the metal on the inside. Not sure if one was more expensive than the other.

 

[Vanzin]

HI,

the fittings are anodised from the outside. Due the process for this it can happen that a part of the inner part will also be anodised. But normally you should see the normal brass.