Chronograph Used for measuring time intervals (also called: Stopwatch). Often constructed as smaller dials in the center of the major dial. Date display The date is shown on the display. Leather Strap This strap is made ​​of leather. Sapphire glass Sapphire is up to 7 times harder than steel, and surpassed only by diamonds on the Mohs scale. This makes sapphire glass a great protection for your watch.