Set of 4 natural stone power stones. Inner diameter is 14cm. Rubber has been replaced. Purified. I'm sorry, I don't know the names of the stones... Available for individual sale. I'm thinking of 550 yen per piece. Buying the set is cheaper. *Please check my profile.* *Please only "Like" if you are seriously considering buying.* *Likes and comments from those not intending to purchase are not welcome.* *Comments before purchase are unnecessary.*