Stretchable yarn interwoven with silicone threads designed for ultracomfort with no buckles or clasps. footnote ¹ Flaws although not dealbreakers: The Mustang has only 8 holes for adjusting (a smaller variety than on all kinds of other bands we tested), and silver is the one color selection for the components. https://andreemrvz.wizzardsblog.com/26748717/manual-article-review-is-required-for-this-article