This is an original WWII headband. The factory markings have since faded, the khaki fabric has frayed, and the leather has dried in some areas. It features the 'double wire' buckle variation, first introduced in early-1942 and later replaced by the standard buckle in mid-1942. This would be an ideal headband for all helmet liners with non-painted steel A-washers (including Hawleys and low-pressure liners).
Early-WWII M1 Helmet Liner Headband (Double Wire)