Gray Boxy Sweater Shirt

Pretty dark gray short-sleeve sweater with boat neck, short sleeves, perpendicular-knit side panels. No maker or materials tags--please see measurements for sizing: Armpit to armpit: 25" across Waist: 24" across Length: 22" Fits me and I wear a large/XL top--but boxy, drapey cut could be worn by many sizes.