The Ocean Band is made from a high-performance elastomer with a tubular design that stretches for a perfect fit, even over a wetsuit. The titanium buckle and adjustable loop keep the strap secure during high-speed water sports. An extension band is available separately if you need extra length for wearing over a wetsuit. The band fits wrists 130–200mm in size. It is compatible with Apple Watch models 44mm, 45mm, 46mm, and 49mm.