The rugged Alpine Loop is made from two textile layers woven together into one continuous piece without stitching. High-strength yarns reinforce the top loops, and the corrosion-resistant titanium G-hook slides easily into the loops for secure fit Material: 95% recycled polyester 100% recycled spandex Band Compatibility The Titanium Milanese Loop, Trail Loop, Alpine Loop, Ocean Band, Hermès En Mer band, and Hermès Scub’H Diving band are designed for Apple Watch Ultra and pair best with the 49mm case size. The bands are also compatible with 44mm, 45mm, and 46mm cases Compatibility for Apple Watch Models: 44mm 45mm 46mm 49mm