Sinn Watch 556 I Leather Red Special Edition 556.010.LEATHER.RED. Sinn watches continue to impress with their sporty and sophisticated designs, perfect for professional men in need of a reliable and striking timepiece. Found within the polished 38.5mm stainless steel case of this Sinn 556 I B 2 watch is the ETA 2824-2 self winding movement which is proudly displayed through the open case back. This impressive movement equips the timepiece with hours, minutes and seconds function, 25 bearing jewels and 28,800 semi oscillations per hour.