Faded chore jacket in a Smaller medium size (S/M, 21.5" pit to pit), most likely early 1970s. 
Classic cut with three patch pockets with grey stitching, five front buttons, one inner pocket and small round collar. Mark on the chest pocket where a logo would have been stitched, shows the darker original colour.
Nice soft cotton fabric. Small marks and signs of wear, repairs on the collar and cuffs (repaired but frayed), please see photos.
Further details about sizing here.