Natutal stone,made of black obsidian bracelet.each bead is polished for comfortable wearing. You'd better put the feng shui bracelet with the head of the pi xiu facing outward when you wear it, and pi xiu will absorb the good luck and wealth from outside for you. As a gift for any special days,it is a caring and thoughtful gift to your family, friends and yourself. Our elastic design allows a one fits all approach while not being too loose on smaller wrists, or too tight on larger wrists. Elastic design fits all wrist sizes,7.48inch size fits more wrist sizes,high elasticity and not easy to break. more durable and firmer than others.