This item is brand new and fits true to size. I am a size 4/6, 135lbs. 5'5" and I am wearing a small. 

It is form fitting on me so if you prefer a looser fit or have a larger chest, I would suggest sizing up. The material has stretch and is very comfortable.

TOTAL BODY LENGTH: 25.5", BUST: 28.5" - MEASURED FROM SMALL * COLOR MAY VARY SLIGHTLY DUE TO MONITOR RESOLUTION