This is 100g of ceramic balls made from Iou-seki, said to be the best source of minerals, making it easy to use. The effects of Iou-seki: Iou-seki is a natural ore mined in Mt. Iou, on the border of Ishikawa and Toyama prefectures. It is characterized by its porous nature, which provides adsorption, water purification, and deodorizing effects, as well as mineral release (improving water quality, promoting plant growth), far-infrared radiation (for bathing and activation), and oxidation-reduction action (for preserving freshness). It is used in various fields such as agriculture, livestock, water treatment, and health goods (bathing and cosmetics), and has been prized as a "medicinal stone" since ancient times. I wonder if this product, like terahertz, is also something that can't be sold on Mercari? Thank you for viewing.