How to differentiate original and fake Apple 5W USB EU power adapter A1400 / MD813ZM/A?
I got here by having the same problem as you and googling it. :)

I got my 5W EU charger (i'm sure now that it's fake) from a local seller, because my brand new SE was for UK market, so i had their three pin charger in the box. The one that i bought had a problem i noticed shortly. When i tried to charge my SE with it, touch sensitivity would go crazy. I compared it with my girls charger (she got it with her 6S in the box, for French market) and it was working flawlessly. There are couple differences between those two. Metal pins are different, fake one is lighter and you can bend the plastic housing a little when you press it harder.
They even made serial number readable, but pins and weight betrayed them.
I will post pics tomorrow when there is daylight so i can make better macros.