We’ve had more than our fill of iPhone 6 mockups, which is why we’re happy to see that mockups for the next-generation iPad Air have started popping up on the Internet as well. Japanese website ASCII Plus has posted several high-quality pictures of a next-gen iPad Air dummy that show us some of the subtle design changes that Apple is planning to make with its next tablet. The least surprising design change is that Apple is making the next iPad Air even thinner than the original, which measured in at only 7.5 millimeters thin. And as you can see in the picture below, Apple has also apparently decided to make the volume buttons recessed while the original iPad Air’s volume