Nike mercurial vortex astro turf trainers junior the nike mercurial vortex astro turf trainers are ideal for wearing on indoor pitches or hard outdoor surfaces the trainers feature full lace up fastening for a secure fit whilst the padded ankle collar and cushioned insole ensure maximum comfort the trainers feature textured grip to ensure maximum traction on a wide range of surfaces trainers astro turf junior lace up fastening padded ankle collar cushioned insole