Descripción en Youtube:
"Langsamer Satz" (1905) by Anton Webern.
The Faust Quartet is:
1st Violin: Wojciech Garbowski
2nd Violin: Cordula Frick
Viola: Ada Meinich
Cello: Birgit Böhme
The quartet is based in Cologne, Germany.
They can be contacted through the website:
http://www.faust-quartett.de/en/start.html