From the website: "The Cosima Nap Dress® is easy, breezy, and totally chic, featuring a fully-smocked (and bra-friendly!) bodice and a crisp, high boat neck fit. You can wear Cosima with flat sandals for a quick out-the-door look, or add a belt and statement earrings for a little something extra. The Cosima Nap Dress® in Black Jersey features a side slit. 92% Polyester; 8% Elastane" This is new with tags, never worn. The material is very soft, it really is the perfect everyday black dress. This is very stretchy so can fit a wide range a sizes. I would say it could fit S-L. See measurements in photos and ask if you have any questions!