Thank you for visiting from among many! It's a free size, but it feels like a size S to M. Adjustable with shoulder straps. I mainly conduct transactions on weekdays. If you have any questions, please comment! (I'm not available on weekends and holidays) I haven't worn it even once, but it doesn't have a tag. It's a home-stored item, so please understand any wrinkles, etc. before purchasing. No returns or exchanges, please. ^ - ^