NIKE Structured Training Belt 2.0, Large Black/Total Crimson Nylon.Steel roller buckle keeps belt securely in placeFirm nylon keeps plastic inserts at lower back maximize support Firm nylon keeps plastic inserts at lower back maximize support Perforated back panel with ventilation channels regulates temperature Anatomically correct design encourages proper lifting technique Content: 30% Polypropylene, 25% Polyester, 25% EVA, 20% Nylon