75% wool, 25% nylon
Quoted from YarnMarket.com, as no mention is made on the Lang website about this yarn:
“Jawoll Aktion Sock Club 2007” Yarn
Using the fiber formula that has made “Jawoll” the premiere sock yarn in Europe, Lang is introducing a special 2007 club for sock connoisseurs. “Jawoll Aktion” is a fabulous collection of exclusive, never-to-be-repeated color combos & patterning sequences available for a limited time & in limited quantities. Five colorways & designs are being produced each month from July through November, so take a look at the images of a finished sock for each option and see just how marvelously diverse the collection of 30 choices really is.