Made with blue natural stones (^^) It's a rubber type, so you can put it on as is. [Inner Diameter] Approximately 15cm [Notes] ◆ Photos taken without processing. ◆ I will cleanse it with a crystal cluster before shipping. ◆ Simple shipping (bubble wrap + envelope) ◆ Immediate purchase OK, first come, first served. Power Stone Bracelet [Qualifications] Power Stone Appraiser / Natural Stone Appraiser / Mineral Therapist / Personal Colorist