When you buy the Mini SD cards, adapter and mini case will send with them, But have you every studied what is exactly inside the adapters?
Some times you buy a memory card from shop or buy from China and after you want to use card reader to copy some data inside your card, you will find out that memory card can not work or can not format! , First at all you will think that your card have problems and will return it to the shop and will ask them to change it, but not all the times the cards have problems, this is the Adapter that can't contact well between memory card and adapter. There is different types of adapters with different prices, some are very cheap and some expensive, if you do not know something, Also you can not see.
So hereby I let you know all you need about it.

For Mini SD as you can see in above picture, there are three types of them.

No.1:
It don't have stable pins because it didn't controlled by some plastic bridge or metal one. Also the pins are not on surface and have a little distance. when you push the memory card in, then maybe the memory card push the pins and make them damage, it's very danger also for your memory cards, because it can connect some contacter of your memory cards together and result probably is burning the chip set.

This is an example:

* As you can see the pins have a little distance from the plastic body so the Mini SD cards totally damaged it.

No.2:
It's the normal one and works well but it will effect on the speed of writing or reading of memory card, that's because of the material of the metal. But as you can see the pins controlled by one plastic bridge and they can not move, also the pins tips are stick to the surface and when you insert the memory card without any problems can connect and it's hard to damage because of the shape of the tip.
Here you can see the big picture of it



No.3 (recommended):
Very high quality but expensive I don't talk more about it, you can see on picture and judge from the information that before I told you.




If you don't ask from your supplier, probably you will get the No.1 because everybody take care about profit, it's very little so why I never understand the suppliers much!

So let's increase our knowledge and protect ourself...
Thanks

I will post about Micro SD and other adapters in the near future.