The Samos swim trunk is an instant classic with a twist. With its hydrochromic technology, a Bunny pattern magically appears when they're wet. Waterproof bag in back pocket.Also available for Kids Woven - 100% Polyester Mechanical stretch, Inside net 76% polyamide, 24% elastaneMade in ChinaRegular fitHydrochromicSilicone Bunny patchMesh liningThree pockets Hydrochromic is a term used to describe a type of material that changes color when exposed to water. In the context of swim trunks, hydrochromic materials are used to create a unique and dynamic look. When the trunks come into contact with water, the material changes color, revealing a hidden design or pattern. The color change is temporary and returns to its original state once the fabric dries.