UHS-I Interface
These are extremely fast cards and are not compatible with Speed class or unrated cards. In my opinion they shouldnt be SD cards and should have a different shape.
They are identified by a 1 inside a "U" shape it only comes on HC and XC cards. The card description should include the UHS-I in the description.
Unless your device specifically calls these out stay away from them. The price should scare you away.
 | UHS-I Bus IF Level 1 UHS |
How fast are they ?
These are rated at 45 MB/s to as high as 90 MB/s
What are they used for ?
These are used for recording very large High Definition Video in Real time
