Ipad size

I use a 9.7" iPad Pro with mine and it just barely fits, with no case on it except the super thin expensive official apple one. It sort of doesn't fit, it pushes up a little bit on the foam part of the device holder but it definitely doesn't put extra stress on the expandable arm.
 
I also use the 9.7" iPad Pro, it's a good fit, but you couldn't go any larger. Upgraded from a Mini 3 made a big difference in seeing the screen on a bright day.
 
I also use the 9.7" iPad Pro, it's a good fit, but you couldn't go any larger. Upgraded from a Mini 3 made a big difference in seeing the screen on a bright day.

I bought an iPad Pro 12.9. Yesterday. 250 off at Verizon. Also ordered the extended mount for it