The Ronda 9013-21 watch movement is a Swiss lever escapement system with hour and minute hands that continuously run. A pusher located at 8 o'clock allows for separate resetting of the hour and minute hands. Additionally, the movement features a resettable second hand that can be operated while the watch is still running. As a manual-wind chronograph, it includes 60-second, 30-minute, and 12-hour functions controlled by a pillar wheel. It also incorporates a sub-second display and shock protection. The Ronda 9013-21 movement was commonly used around the year 1975.