Last year’s iOS devices shipped with Bluetooth 4.0 connectivity, but according to Apple’s website, the iPhone 6, iPhone 6 Plus, and iPad Air 2 now boast the latest Bluetooth 4.2 technology.

“In 4.2, Bluetooth Smart is up to 2.5x times faster with a huge packet capacity increase — nearly 10x more versus previous versions,” Apple boasts. Updated tech specs and comparison pages on Apple’s website show that iPad Air 2, iPad mini 4, iPad Pro, iPhone 6, iPhone 6 Plus, and the latest iPhones all ship with this technology, leaving only the iPad mini 2 and iPhone 5s on Bluetooth 4.0.

What makes these pages particularly interesting is that the iPhone 6, iPhone 6 Plus, and iPad Air 2 originally shipped with Bluetooth 4.0, and it’s not totally clear how or when they were updated.

iPhone-6-Bluetooth-updated

It could be that Apple rolled out new firmware to update its Bluetooth technology — perhaps with iOS 9. Some devices that shipped with Bluetooth 4.0 were capable of being updated to Bluetooth 4.1 via software updates, so that’s certainly plausible.

There’s also a possibility, however, that Bluetooth 4.2 requires new hardware to enable the significant speed and capacity improvements Apple mentions, and therefore can only be found in recently-manufactured iPhone 6, iPhone 6 Plus, and iPad Air 2 units.

We’re hoping Apple will clarify the updated product pages soon, but it seems more likely it will leave us guessing over this one.