The Ruhla 28-33 Quartz was based on the mechanical movement caliber 24. The first test series of 3,000 pieces were made in 1972. The commercial production started in 1977. This watch was the first quartz watch in East Germany. It has a curious and clearly visible stepping motor. At the Leipzig Fair of 1978, the second quartz watch of Ruhla, caliber 14, with a small quartz crystal was introduced. The commercial production started one year later.