The Certina 13-20 watch movement, produced by Wostok Watch Factory Tschistopol, features an indirectly driven minute and second hand mechanism that enables a relatively large balance. The original version of the movement was equipped with a Breguet hairspring and a fixed stud carrier, while the newer version utilizes a flat hairspring and different mobile stud carriers. This manual wind movement includes a sweep second hand and the option for a hack feature. The Certina 13-20 was commonly used during the period of approximately 1955.