Maximum SD Card Speed?

Does anyone know what SD card standard and/or speed classes the Key2 supports? Mine is coming soon, and I want to have as fast a card as possible for it, but I also don't want to waste money on a faster card that the phone won't get the speed benefit of.

I've done a bunch of Googling, including on the Snapdragon 660 itself (or, separately, the Key2), but no dice.

This is what I'm talking about, btw:
https://www.sdcard.org/consumers/cho...***/index.html

Thanks for any help!

Best,
Jef