A few hours ago, we learned that our metal watch bands do not adequately fit the Series 4. A few customers who've had our bands from their previous series tried them on their shiny new Series 4 today and they didn't fit. I rushed to the Apple store and confirmed this as well, to my huge disappointment and dismay.
I know, Apple said that all previous bands fit Series 4 and that nothing changed, but for us, something changed. We've always prided ourselves in manufacturing to a more precise fit, and now it's finally come back to bite us. They changed something and we're going to figure out what in the coming days as we purchase our own Series 4 samples and work with the factory engineers to determine just what they moved or made smaller. It only takes a difference of 0.05mm to not fit at all at this level of precision.