Speedo Big Boys' Short Sleeve Swim Rashguard Tee 100% Polyester Loose fit rashguard styling for long wearing comfort Small = 5-6, medium = 7-8, large = 10-12, x-large = 14-16 Block the burn upf 50+ protective fabric to safeguard against sun's harmful rays Quick drying exclusive speedry water repellant fabric Made by speedo, the world's no1 swim brand