Truman Cap The Truman Cap is a six-panel style made from heavyweight herringbone fabric. The cap also has a firm, curved peak. An artificial leather Square Label appears on the front. Specifications: Head circumference: 53 - 59 cm / 20.8 - 23.2 inch 80% Polyester, 20% wool Garment-washed Unstructured Six panel, lined at front panel Firm, curved peak Adjustable strap with metal buckle Artificial leather Square Label