Sinn watch 857 utc testaf bracelet 857040 bracelet sinn watches are renowned for their aviation inspired designs and this sinn 857 utc testaf watch continues this tradition by bringing to life an aesthetic reminiscent of cockpit navigation clocks and their rapid and clear readability the bead blasted stainless steel case which boasts especially scratch resistant tegiment technology hides the eta 2893 2 self winding movement with 200 metre water resistance and air dehumidifying technology