Beginning in the late 1930s through WWII, the CPO shirt was standard issue to Chief Petty Officers of the United States Navy. Calling the Norse Projects Silas wool overshirt a shirt is a bit of a misnomer -- this piece of outerwear could easily double as a lightweight jacket. The Silas' substantial construction is made from an Italian wool blend and features two patch pockets, a stitched pen holder, side seam pockets, all twin needle stitched for strength. Italian corozo buttons finish the look.