Cal. 2510 was produced in the initial heyday of quartz movements, when the accuracy of this new technology was highlighted. Therefore, it has a highly unusual adjustment mechanism An inset pusher at 4 00 advances the seconds hand one second per press, corresponding to the monthly deviation expected. If it is held in, the movement is stopped, enabling correction backward. The crown adjusts only the hour hand and date in second position, leaving the timekeeping and minute hand running, intended for use when traveling. Third position allows the time to be corrected as usual.