I used this for about a year when boiling water. Please check the photos as there is rust. Although iron rust is said to be harmless to the body, please refrain from purchasing if you are concerned. Easily replenish iron with hot water or cooking. The design is attractive for its ease of use that fits into everyday life. Tetsumaro allows you to easily replenish iron by putting it in when making hot pot dishes or boiling water. The iron that dissolves from "Tetsumaro" is called "ferrous iron," which is more easily absorbed by the body than "ferric iron" and is effective for iron replenishment. Retail price: 1320 yen Please refrain from purchasing if you are a nervous person as this is a used item.