Sinn watch 856 s leather 856023 leather sinn watches are renowned for their aviation inspired designs and this sinn 856 s watch continues this tradition by bringing to life an aesthetic reminiscent of cockpit navigation clocks and their rapid and clear readability the black hard coated stainless steel case which boasts especially scratch resistant tegiment technology hides the sw300 1 self winding movement with 200 metre water resistance and air dehumidifying technology housed beneath the