Threadrock Big Boys' If You Mustache I'm The Big Brother Youth T-Shirt Design exclusive to Threadrock 100% preshrunk cotton; seamless rib knit collar; taped neck and shoulders; double-needle hemmed bottom and sleeves Sizing: XS (2-4), S (6-8), M (10-12), L (14-16), XL (18-20) *Sizing Note* Our youth tees run slightly small. We recommend ordering a size up.