This is the back, the heels -
It is 70% superwash wool, 25% nylon, 5% other (other???)
It is #1, super fine with 191 yds.
This is the book it came from - "Sock-Yarn, One Skein Wonders" Edited by Judith Durant. This is a great book! Lots of great patterns! This book is from my own collection.
Or from B&N - HERE