The men's Parker swim trunk has a hydrochromatic pattern that magically reveals itself when the quick-dry material is wet. Waterproof bag included in back pocket. Also available for KidsWoven - 100% polyester mechanical stretch, inside net 76% polyamide, 24% elastaneMade in ChinaSwimHydrochromicHydrochromic swim trunkColor-changing swim trunkWater-Activated bathing suitQuick-dry swim trunkBeach shorts 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.