This is a replica of the U.S. Army M-41 HBT Jacket.
In 1941, the U.S. Army introduced the M-41 split suit as an alternative to the Denim Work Suit. This new suit included a herringbone twill jacket, a pair of herringbone twill pants, and a Daisy Mae Hat. The suit is suitable for civil engineering work and is also used as a summer combat uniform.
The suit was issued for a short period of time, from 1941-1942, and was only made for about a year. Therefore, its circulation in the second-hand market is minimal, and it is one of the very rare styles.
The M-41 Jacket is defined as a lightweight jacket, labeled "SPEC. P.Q.D NO. 45".
It comes in the shape of a denim jacket, with a double fold at the back to ensure plenty of room to move, and adjustable tabs at the back waist, with "13-star buttons."