This pair is in a stretch nylon blend that's both water resistant (so spills and showers won't slow him down) and made with UPF 50+ sun protection. They're crafted in an environmentally friendly fabric that incorporates 65 percent recycled nylon and is made at Everest, a mill committed to sustainability practices. Nylon/spandex. Elastic waistband with tacked functional drawstring. Off-seam side pockets, back patch pocket. Machine wash.