Nike - Swim Boy's Hydrastrong Jammer (Black)Nike Swim Boy's Hydrastrong Jammer has a form fitting cut to reduce drag in the water when racing. Chlorine resistant fabric gives it durability while an adjustable drawcord, inseam gusset, and ergonomic, flat seam construction allow for comfort in motion. Body: 53% Polyester 47% (Pbt); Lining: 50% Recycled Polyester 50% Polyester INTERIOR DRAWCORD for comfort and adjustability LINED for better fit and security FLAT SEAMS for reduced chafing Nike