Margaritaville Sz S Blue Pullover

Jimmy Buffett's Margaritaville Sz S Blue Lightweight Fleece Lined Pullover Windbreaker There is a zippered pocket on the inside back and I have no idea what it's for Please let me know if you have any questions or need any additional photos Approximate measurements: Underarm to underarm - 22" Top to bottom - 27" Sleeve length - 24" est. as there are no shoulder seams Shoulders seam to seam - 21" est. as there are no shoulder seams