U.S. ARMY, CIRCA 1926-1937, TYPE II, COLLAR DISK, CAVALRY, MACHINE GUN Measures approx. one inch in diameter. Screw back. The distinction between Type I and Type II disks is minor and is one made by collectors rather than the military. Type I and Type II disks continued in use until the advent of the Type III disk and likely were issued until stocks of them were exhausted after 1937, which was the usual practice by the Army. Type II disks were also one piece screw post disks but have a more intricate background pattern than the Type I disk. The pattern consists of a series of diagonal cross hatched lines with a pattern of shields or acorns in the squares formed by the lines. This background pattern was established as the sole official one by Army Regulations AR 600-35 of December 31, 1926 but existed as a manufacturers variation prior to that time. Prior to 1926 at least six different background types were in use and Type II background appear on disks dated to 1919 according to Albert Scipio. The regulations issued on December 31, 1926 also abolished the standing collar and introduced a label, rolled collar coat. The collar disks were then worn on the upper collar of the coat's lapels. There are also a few disks with a Type II background produced that were two piece with a branch device that could be removed for cleaning similar to the Type III disks that would follow.