If you have a desired inner circumference, please be sure to let me know before purchasing. It will cost an additional 50 yen for every 1 cm increase. Reducing the size is free. Inner circumference: Approximately 15cm (stretches) Blue Cat's Eye 10mm Cracked Crystal 8mm Onyx 8mm Rock Crystal 6mm Rondel Cracked crystal is said to possess powerful energy, and it is said that cracks occur because of this, making it even more powerful than crystal. Polished ones were used as sacred objects and divination tools. It is especially good at warding off evil and purifying. It will purify the owner's mental traumas and negative emotions, making them pure. Onyx, known as the "stone of protection," has been treasured as a talisman and amulet since ancient times. It is said to have a strong power to ward off evil and absorb negative emotions. Onyx takes on not only malice and envy from others, but also negative emotions within oneself. *Because they are natural stones, the colors and patterns may vary. *The color may differ from the actual product due to lighting. In addition, it may contain cracks and inclusions unique to natural materials. Please understand this beforehand.