NIKE JR Mercurial Vortex II Kid's Soccer Shoe Soft, textured synthetic leather upper molds to the foot for a responsive fit and explosive speed with total control. Lace-up closure for a secure, custom fit. Injected rubber outsole features both conical and bladed studs for optimal traction on firm, natural surfaces. Contoured sockliner for added cushioning and comfort. Firm-ground (FG) soccer cleats for use on short-grass fields that may be slightly wet but rarely muddy.