NWT Ultra-tight, second-skin fit for a locked-in feel. Strategic compression promotes muscle tissue repair, leading to shorter recovery times & reduced soreness. 4-way stretch construction moves better in every direction. Material wicks sweat & dries fast. Anti-odor technology prevents growth of odor-causing microbes. Smooth, flatlock seam construction. Nylon/Elastane. Would most likely fit like XS. Although listed as men's, it may fit a boy who plays sports since it is really small.