The Sinn U2 case is made out of German submarine steel that is guaranteed to be corrosion-proof, as well as impervious to salt water. The bezel is almost scratch-proof due to a process called “Tegiment” which causes steel to harden to ceramic levels. In addition to being a true ISO 6425 dive watch there is a GMT (second time zone) function that uses the inner 24-hour ring and the large black Sword-shaped hand with a red tip.

Jason Pitsch
Posted by:Jason Pitsch

Jason Pitsch is the Founder of Professional Watches. He appreciates good design and engineering in everything from architecture to automobiles to cameras to clothing. Yet his focus for the past decade has remained consistent on covering just one type of craftsmanship: watchmaking.