Hamilton American Classic PSR Digital Quartz 40.8mm X 34.7mm Watch Screw In Crown this timepiece sets a new Bracelet Size:7.9 IN this timepiece sets a new standard for precision Movement Description: The self winding mechanical movement beats at a remarkable frequency of 25 In 1970 Hamilton changed the way the world told time with the debut of the Hamilton Pulsar Fifty years later the Hamilton PSR celebrates the launch of that revolutionary first digital watch Today a hybrid display and a stainless steel case bring this game changing invention back to the future Features Case Size 408mm x 347mm Dial Colour Black Crystal Sapphire Water Resistance 10 bar 100 metres Anti Reflection