2 Not Supported: Anything That Requires Additional Drivers
iOS is not a full-fledged computer operating system, so it comes with some restrictions. We mentioned the inability to read most file types on the iPad Pro, but there’s also another type of device that isn’t supported by the new tablets.
Basically, anything that requires you can install additional drivers to your operating system. While there are still quite a few basic accessories that will work, this flaw won’t let you use the entirety of available USB-C devices currently on the market. Again, Apple could change this in a future version of iOS.