A Swiss, mechanical stopwatch in a 50mm diameter chromed case in good condition, a few surface scratches but nothing major. Wound, started and stopped by the crown and zeroed by the button on the case edge. When the crown is pressed to stop the movement, it only stops as long as the crown is pressed. It can be zeroed at this point, but it starts as soon as the crown is released. Other than this, it is running and keeping time.