Joe's USA - Youth Long Sleeve Polos - School Uniform Shirts. Sizes Youth XS-XL Joe's USA - Youth Long Sleeve Polos - School Uniform Shirts.Sizes Youth XS-Youth XL. our comfortable classic polo is anything but ordinary. With superior wrinkle and shrink resistance, The silky smooth pique knit resists wrinkles while the classic long sleeve style looks great on everyone. 5-ounce, 65/35 poly/cotton pique. Flat knit collar and cuffs 2-button placket on XS-M. 3-button placket on L-XL Metal buttons with dyed-to-match plastic rims. Double-needle armhole seams and hem. Side vents Youth Sizes: XS (4), S(6-8), M(10-12), L(14-16), XL(18-20)