Sinn Watch 556 A Leather Red Special Edition. Sinn watches are renowned for their aviation inspired designs, and this Sinn 556 A watch continues this tradition by bringing to life an aesthetic reminiscent of cockpit navigation clocks and their rapid and clear readability. The satinized stainless steel case embraces the ETA 2824-2 self winding movement with hours, minutes and seconds function and a date display at 4 o clock. The automatic mechanism also boasts 25 bearing jewels, 28,800 semi oscillations per hour and shock and anti magnetic resistance.