The Junghans J38C/1 watch movement features a pin-lever escapement and incorporates an indirect minute hand friction clutch on the barrel. The specific differences between the 677 and 680 models are not specified. This movement functions as a simple manual-wind chronograph with a sweep second hand that allows for start/stop actions but lacks a reset feature. The period of utilization for this movement is approximately around the 1950s.
The Junghans J38C/1 features the following functions:
Simple manual-wind chronograph, 60s, start/stop of the sweep second, no reset feature