These are GENUINE Thomastik strings, made in Austria.  Beware of other online sellers who are selling fake imitations!

With Stainless steel E -  titanium design, removable titanal ball end.

Made with a highly flexible, multi-strand synthetic core, provide the tonal warmth and feel of a gut string while being impervious to changes in humidity. The sound is Clear and Colourful, with a stable intonation and they are rich in overtones. One of the world’s most popular strings! 

E - Titanium design stainless steel
A - Aluminium wound
D - Silver wound
G - Silver wound