Size Medium is on the Mannequin.
Approx. Measurements -
Size Small (4-6)
Underarm to Underarm 19" Shoulder to Hem 21"
Size Medium (8-10)
Underarm to Underarm 20.5" Shoulder to Hem 21.5"
Size Large (12-14)
Underarm to Underarm 22" Shoulder to Hem 22"
Size X-Large (16-18)
Underarm to Underarm 23.5" Shoulder to Hem 22.5"