“AN” series such as AN6552 and AN-J-3A are the jackets developed by US Army Air Forces and US Navy during the WWII aimed to use in common. Most were mainly worn by Navy pilots, however, the Army Air Forces also adopted the "AN" series by replacing leather with textile fabrics, creating a lightweight, warmth-retaining jacket for the mid-range temperature zone. The outer material is rayon-cotton, which at that time was valued for making raincoats because it easily repelled rain, etc. The color is the same as that of the brown leather used in the "AN" series. Most of the detailing is the same as the G-1 "AN" series, including a mouton collar, two patch pockets with flaps on the lower front, bi-swing action pleats on the back, and a ribbed hem with a single layer of ribbed fabric. "Bird Man" Chuck Yeager tested the jacket in an actual flight. Yeager's rank at the time was captain, and in respect of his rank, epaulettes were added to sew the rank insignia on, which was the detail not found on the G-1 series but was carried over to the mass-produced B-10 series. Since there is no evidence of this brown B-10 being worn by any pilot other than Yeager in any photographic documentation of Air Force history, it is assumed to be a historical jacket specially prepared expressly for him.