Officially designated as 'Jacket Winter, Combat Tank Jacket' came from the Winter Combat Uniform which was developed in 1941, the uniform consisted of a cloth helmet, a jacket and overall. All 3 parts of the uniform were made from olive drab (OG) #3 cotton twill The jacket was lined with brown kersey wool (blanket like material) & had a cotton outer with light brown knitted cuffs along with the knitted waist band, a bi-swing back, not a bulky jacket at all which improved crouching or sitting for the crewman’s mobility inside a tank’s cramped interior. It was originally intended for all branches of the U.S. Army as a general issue winter uniform. It was re-designated for use only by U.S. Armoured troops that were assigned to tank and reconnaissance units and armoured infantry units in half-tracks who needed cold weather gear when fighting out of these armoured vehicles since they didn't have great heating systems thereby getting its nickname - the Tank Jacket.

This jacket was issued in two variations. The first model P. Q. D. Spec. No. 26 was produced with exterior open patch pockets and a double-faced cotton twill wind flap behind the zip closure, later replaced with a wool-backed wind flap. The revised Spec. No. 26a jackets came with interior hidden pocket & cotton-lined slash pockets along with the wool-backed wind flap that appeared on later Spec. 26 jackets. Stylish good looks, comfort, practicality and warmth of the Tanker Jacket made it one of the most popular articles of clothing used by the G. I. in World War II, including the officers.

It still managed to find its way into the hands of many other units of the armed forces, such as the Infantry, & the Air Force, where it can occasionally be seen worn by Air Force pilots as well as airborne paratroopers due to its warmth from the wool blanket lining & was far superior to the M41 Field Jacket. 

Collectors covet the first model jackets Spec No. 26 costing thousands on the collector market.