80 Polyamide/20 Lycra Prime. Employing Lycra Prime which has 400% better Chlorine/Bacteria resistance than regular Elastane. Excellent Stretch memory, working with your body movement, but retaining shape and firmness. Polyamide yarn has moisture management function as you transition from one sport to the next. Polyamide yarn on outside so abrasion resistant, Built to last through demands of swim / bike / run. Optimum knit gauge to allow for speed in water, but max air flow out.