I thought S.U.G stands for Sächsische Uhrentechnologie GmbH Glashütte (SUG) the company that makes the cases for Sinn watches.
From their history page:
"In 1883, a Winterhur watchmaker by the name of Gottlieb Hauser brainstromed the idea for the Swiss Watchmakers Corporation (Schweizerische-Uheremacher-Genossenschaft) as a distributor for standardized Swiss watch components."
http://www.sugwatches.com/
I thought S.U.G stands for Sächsische Uhrentechnologie GmbH Glashütte (SUG), the company that makes the cases for Sinn watches.
"SUG is the only German case manufacturer certified for the demanding standard DIN 9002." Sinn Catalog
This is my first time posting please be gentle. I recently purchased a SUG off ebay and found the watch case was very nice. It was the throttle model in yellow. In the first 2 monts the quartz watch stopped 3 times. I took the watch to have the battery checked and it was fine. When the back was opened it read China on the inside of the back. The problem with buying them off Ebay is the sellers are buying them from one of SUG's bid sites and reselling them on Ebay. I called SUG in Texas to find that the warranty is only extended to the original purchaser and not the secondary. The seller will not answer my emails so I was forced to contact my credit card company and return the watch. Hope this helps others.