This Sock/Fingering weight yarn consists of 35% Cotton, 25% VIscose, 20% Silk, 20% Polyamide...a lot of mixture providing some great strength in a sock yarn.  Depending on what needles/hook you use, you can possibly pull DK weight as well.
 
Sonata is a 100 gram skein holding approximately 393 yards...another skein with a ton of yardage.
 
Make sure you get enough to complete your project.