Specification (approximate): Case Diameter: 43mm Case Thickness: 13mm Band Width: 21mm Band Length:21mm 100% New with tag and high quality; What can I do when the watch stop? Fully winding up spring need be turn the crown clockwise 20-30rounds to start the watch and give it some reserve power， Self-winding automatic movement watch needs to wear every day (for about 8 to 12 hours a day)， The Automatic Wrist Watch is wound by the motion of the wearer's arm，that is wound by wrist morements thanks to the rotor， this device winds the watch's mainspring automatically using the natural motions of the wrist, with a rotating-weight mechanism. If an automatic watch is not worn for a day or two, Or the natural movement of the wrist is very small,it will wind down and need to be Supplementary winding by hand to get it started again,turning a Crown winding attached to a ratchet which twists the mainspring tighter,Energy is stored in the mainspring manually by winding it up. and when the crown is pulled out a short distance allow the hands to be turned to set the watch.