How can I find out more about my watch based on its serial numbers? How can I identify the production quantities for my watch model/my watch movement? The last 2 numbers show the model of the watch as an example the A17605 is a steel Breitling shark automatic non chronometer with eta 2824 movement. Please remember that this is just an approximate guide and can not be used as a 100% accurate outlook as per how old your watch might be.