Taking design cues from the heavy wool shirts issued to Petty Officers, the CPO Wool Jac-Shirt is the newest addition to our overshirt legacy that spans five decades.

The U.S. Navy issued heavy woolen shirts to its senior enlisted men beginning back in the 1930s to satisfy the need for a warm, protective shirt that would serve in the unforgiving weather found at sea. Filson has made heavy wool overshirts for service in the wet and cold Pacific Northwest since the 1970s. This is a natural pairing that just makes sense.

This Jac-Shirt is built with 24-oz. 100% wool, a fabric that has protected us from all manner of weather for centuries. Wool’s unique fiber structure allows it to resist moisture and insulate even if it gets wet. And wool is durable–individual fibers have been subjected to abusive tests and maintained their integrity far longer than other natural fibers.

The chest pocket flaps secure with natural horn buttons to keep contents safe, and the sleeves are button-adjustable. The curved hem design allows for wear tucked or untucked. A center-box pleat in the back yoke allows unrestricted ease of motion. This is a cold-weather shirt That’s built for decades of reliable service.