Made of gauze-like fabric, 100% cotton. It's navy blue and see-through when held up to the light. There's a ribbon of the same material in the front, and it opens up to around the chest. It's new, but only has a tag that says size 15. It looks like a size M to L. For those who are not overly concerned, thank you. I plan to ship it via Rakuraku Mercari delivery either on the same day or at the latest, the next day.