New 'Solo Loop' Style Bands Optimized for Apple Watch Series 4 and Later
Apple has new band styles for the Apple Watch out today, called the Solo Loop and Braided Solo Loop. In the details on each band's store page, Apple points out that these bands are aimed at the Apple Watch Series 4 and later watches.
The reason for this is because these new bands come in eighteen different size options. Apple gives customers a printable tool to find their perfect fit for the Solo Loop bands on Apple.com.
Once you print the tool out and wrap it around your wrist, Apple gives you a number of 1-12, which corresponds to which case size (40mm or 44mm) and band size you'll need. There is some overlap between 40mm and 44mm case sizes, increasing the band size count to eighteen.
These sizing options omit the older Apple Watch case sizes of 38mm and 42mm. To keep things simple, Apple is noting that the bands are only compatible with modern models of the Apple Watch, essentially including Apple Watch Series 4 and later.
Still, these new bands should technically fit on the equivalent 38 and 42mm casings from Series 3 and earlier, but you may have to size up a bit to account for the slightly smaller casing if you want to use one of these bands with an older watch. We should get more detailed information about fit and compatibility for these new bands once they start arriving to customers later this week.