Nike Structured Training Belt Structured Training Belt Steel roller buckle keeps belt securely in place Firm nylon Plastic inserts at lower back maximize support  Anatomically correct design encourages proper lifting technique  Perforated back panel with ventilation channels regulates temperature MEASUREMENT IS AROUND NAVEL TO LOWER BACK, NOT PANTS WAIST. Size Chart: S/P=24"- 30", M/M=30"- 36", L/G=36"- 42", XL/TG=42"- 48