Along with the Apple Watch Series 6, Apple introduced a new watch band called the Solo Loop. It has no clasp and is instead made from an elastic polymer, so users can just slip their watch on and off. They are not one-size-fits-all, however. There are nine different sizes, from 4 to 12.
https://www.techspot.com/news/86842-apple-new-solo-loop-bands-have-returned-watch.html?utm_source=dlvr.it&utm_medium=blogger
https://www.techspot.com/news/86842-apple-new-solo-loop-bands-have-returned-watch.html?utm_source=dlvr.it&utm_medium=blogger