Barbour Men’s Snap Button Long Sleeve Button Down W/ Zipper Pocket Size Large?

Barbour Men’s Snap Button Long Sleeve Button Down W/ Zipper Pocket Size Large? No size marking or style number to reference. Hadn’t seen anything like this before with Barbour so not sure if it’s a layer piece or a button down casual shirt. Very nice and in perfect condition. Across chest, pit to pit is 22 inches and by my size, I’d say slim fit Large.