Hello....this is seriously my favorite product from Wanelo EVER. This is an absolute gorgeous piece. I love the off the shoulder design. It comes with a slip underneath but it is somewhat sheer so make sure you wear nude underwear. The material is super nice and the design is to die for. Cassie actually had a prom dress with a super similar design and she looked stunning, so this fabric awesome. I'm 5'7 and there isn't a size tag but I'm going to guess this is probably a M.