Cal. CO753 nickel-finished lever movement black dial applied Arabic and horizontal baton numerals three subsidiary dials constant seconds 30 minute and 12 hour registers outer calibrated 1/5th seconds ring with nauticual flags eccentric date aperture between the 4 and 5 oclock oversized polygonal water-resistant-type case two rectangular chronograph buttons with security locks in the band screw back with Corum Grand Prix logo screw-down crown case dial and movement signed Corum rubber strap with buckle