Apple introduced new iPads and a bunch of new accessories today, but instead of using the launch as a time to simplify, knowing what works with what is more confusing than ever.

Let’s focus first on the 10th-generation iPad, which got the biggest changes. Its new design more closely matches the company’s other recent iPads, with a USB-C port, slimmer bezels, and Touch ID on the sleep / wake button, just like the iPad Air and iPad Mini. From pictures, you’d be hard-pressed to tell which is the base model iPad and which is the Air.

The similarity to those other two iPads might make you think this new one supports the second-generation Apple Pencil, which can magnetically stick to the side of tablets for charging and pairing. But it doesn’t: instead, the 10th-gen iPad only works with the old Apple Pencil, and since that stylus has to be charged from a Lightning port, which the new iPad lacks, you’ll need a special dongle to hook it up.

Maybe you don’t care about the Apple Pencil but instead want the latest and greatest in Apple’s keyboard cases. For the new iPad, you can add on a new Magic Keyboard Folio, which offers a 14-key function row for easy access to things like volume controls.

A function row seems like a great thing to have with an iPad Air or iPad Pro, right? Alas, the $249 Folio is only compatible with the 10th-gen iPad. And Apple hasn’t updated its keyboard covers for other tablets to add in the function keys despite the fact that the company also announced upgraded iPad Pros. 

Apple’s entire iPad accessories ecosystem now feels fragmented and confusing, especially when many of the existing accessories already work across devices. The second-generation Apple Pencil works with both sizes of the iPad Pro, the iPad Air, and the iPad Mini, for example. The smaller Magic Keyboard case works with both the 11-inch iPad Pro and the iPad Air, but it isn’t compatible with the new iPad even though that tablet is nearly the exact same size.

No, really, it’s a matter of millimeters. Here are their individual measurements:

• iPad: 9.79 inches (248.6mm) by 7.07 inches (179.5mm) by 0.28 inch (7mm)
• iPad Air: 9.74 inches (247.6mm) by 7.02 inches (178.5mm) by 0.24 inch (6.1mm)
• 11-inch iPad Pro: 9.74 inches (247.6mm) by 7.02 inches (178.5mm) by 0.23 inch (5.9mm)

Said another way, if Apple had shrunk the new iPad just a bit, it could have been compatible with the smaller Magic Keyboard. Presumably, that would have also meant the Magic Keyboard Folio with its 14 glorious function keys could have worked with the 11-inch iPad Pro and iPad Air, too.

Apple knows how to make things compatible across gadgets; the company built its name on making things that just work. But for this iPad launch, Apple instead chose to make its tablet ecosystem more fractured.