The Midweight Power Wool™  Zip is an upgraded midlayer that uses Polartec's sustainably harvested wool in combination with a synthetic exterior to blend the temperature regulating benefits of wool with a quick-drying polyester exterior. Our wool line was named the Jay collection to honor the great pow that region captures and the many lines you'll be able to score because you've added wool to your layering system. 
 
 
This fabric is made up of 51% Poly, 42% Wool, & 7% Spandex.
 
The Men's Medium weighs in at 9.1 oz.