Lightweight material and comfortable version, no matter what the occasion, it is a long version of the unbeaten military uniform long windbreaker, how can you not have it? Historical origin of commodity styles: This type of jacket is also called M-51. Unlike the popular military uniforms, most of the familiar M-65 and M-A1 models were born during World War II. Only M-51 was born in 1951. During the outbreak of the Korean War, the US military moved from the tropics to the frigid zone, which gave rise to this long uniform with an inner liner to keep warm. It was also named after the year "51".