Whats the Difference between CZ880 and CZ88

I have a 128gb Extreme Pro ( CZ88 ).

And I noticed there is a USB 3.1 Model ( CZ880 ).

The Older One CZ88 Appears to be about $20 Cheaper tahn the Newer USB 3.1 Model.

Also I am confused by the Read/Write of Both.

Is there any speed difference between the 128gb model and the 256gb model ( CZ880 ).

Could somone please explain their differences and which one is the Fastest.

Many thanks