With the AEROCHARGE FUSION STZ were taking indoor shoes up a notch. Another sterling member of the popular Aerocharge collection, this shoe marries smart aerocharge outsole with a full knit reinforced upper and in-sock construction. Launch into sudden fast strides and twist with confidence with strong internal elastic band for stability and lockdown. External heel counter and double row lace eyelets allow optimum flexibility and breathability. Get ready to smash your goals in these performance boosting shoes to accompany you every step of the way. Medium/wide fit: choose your standard size for a slightly wider fit or go down ½ size for a narrower fit.