Hamilton H64615555 Khaki Aviation Pilot Day Date AutoProduct Highlights Inspired by the pioneering spirit of early 20th century aviators, Hamilton has recreated the aviation watches of that era using modern materials such as stainless steel and sapphire crystal. This new timepiece features a 42mm case that harmonizes perfectly with an automatic movement. Model Number H64615555 Caliber H 40 Collection Khaki Aviation Movement Automatic Functions Date display, Day display Case Size 42mm Dial Color Silver