Sinn Watch 556 I RS H Link Bracelet 556.0106 H Link Bracelet. Striking form, sparse dial design, superior readability, characteristic SINN features which highlight the similarities between the Sinn watches 556 series and our pilot and navigation cockpit clocks. The accentuation of the hours, minutes, seconds and the date plus the satinised stainless steel case are what give the watches their sporty yet elegant appearance. The crystal of the 556 watches is made from sapphire crystal, as is the transparent back which provides an intriguing insight into the filigree mechanical movement inside. The model 556 I RS has a special feature: The red second hand is in a harmonious contrast to the black of the dial and the white of the indices.