Vintage Tissot Antimagnetique (add more to comments below)
The Tissot caliber 27 was released in 1936 and produced until 1949 in Switzerland. Following 1949, many variations were introduced and manufactured until about 1961. The movement pictured here is a caliber 27 without an anti-shock system. We previously posted this caliber 27-1T which is the same movement with an Incabloc shock system. The 27-1T was produced in between 1950-1952.