Thank you for viewing. This item is unused, but was purchased 5 or 6 years ago, and the string has not been replaced. It uses approximately 12mm jade beads and 14mm crystal dragon beads. Dragon power stones are said to give you the power to overcome difficulties and achieve your goals. The inner diameter is approximately 17cm. I think it can be worn by both men and women. Although it is unused, it is still a used item, so please understand this before purchasing. There are no accessories such as a warranty or box.