The Levi’s 506XX denim jacket is one of the most iconic models ever produced. This model originally hit the market as early as 1905. Levi’s made a total of 6 different versions of the 506XX jacket over the years, from 1905 to 1947. Today this jacket model is also known as Type 1. Around 1917, the jacket design was named number one, later moving to type 1. And the transition from the word blouse to jacket occurred in 1938, when the word jacket was first used in the western clothing catalog, Dude Ranch Duds. Early edition 506XX models only have a front pocket, a silver buckle in the back, and no flap covering the front pocket. Later models of the 506XX jacket have a flap over the pocket. The famous Red Tab – Big E – appeared on the 506XX models in 1936, the year Levi’s introduced its famous Red Tab. The word Levi’s was written on only one side of the Red Tab. This changed with the birth of the next jacket in 1953, the 507XX (also known as Type 2) model.