(From Filson).

A warm overshirt made with 100% virgin wool.

Introduced some fifty years ago, the Filson Shirt Jacket serves as a heavy shirt, overshirt, insulating layer, or light jacket. It has protected more outdoorsmen in a wider range of conditions than we could begin to count.

Sewn in our Washington factory, our original Jac-Shirt is an outdoor staple that provides warmth in all conditions like only 100% wool can. The 18-oz. fabric is crafted with a tight weave that delivers an optimum balance of breathability and wind resistance, while providing durability for decades of service. Wool has a complex fiber structure that makes it naturally water-resistant, moisture-wicking and warm even if it gets wet. Wool also resists odors, making care and maintenance a simple affair. Despite science's best efforts, to date no man-made material can provide the all-around performance of nature’s original miracle-fiber.

Our Jac-Shirt has a straight hem for untucked wear. Being designed active use, it's cut with room to move without binding when worn over a shirt or heavy base layers. The two chest pockets feature buttons that are hidden, so they don’t show with the pockets unbuttoned.