This is a nifty vintage Union Bay baseball-style t-shirt from the 90s. Made in USA, it's a heathery brown body with heathery beige 3/4 sleeves and a crew neck.
 
Pre-owned, used; in good overall condition EXCEPT FOR what looks like a bleach splash on the back body. 
 
Marked as size L or large BUT I think it's a kid's size large. Please read the measurements to see if they look like what you need.
 
Pit to pit- 19"
 
Chest- 38" around measured at the underarm seams
 
Center front length- 17 1/2" from neck to hem