What stemware company uses an etched S with a crown on top as a logo?

Spiegelau glassware has a logo with an S and crown.

On 4/16/1968, a U.S. Federal trademark registration was filed for S.

This trademark is owned by KRISTALLGLASFABRIK SPIEGELAU, G.M.B.H.,

SPIEGELAU (BAYER WALD) ,. The USPTO has given the S trademark serial number of 72295744.

To view image, please refer to the links listed below.