The Venus Cal. 188 is a cam-switching chronograph movement introduced in 1948 and the forerunner of today’s ETA/Valjoux 7750 family. It was a revolutionary movement, much cheaper to produce than contemporary column wheel movements, yet still full featured.
Cal. 188 features small seconds at 9:00 and a 30 minute chronograph counter at 3:00.
Cal. 188 was introduced in 1948 and updated around 1953. It was improved and re-launched as Valjoux Cal. 7730 in 1969.