Ideal for teapots. Teapot rattler will alert you when your water has reached a boil. The rattler will clack on the bottom of the teapot. Can also be used in smaller pots such as a saucepan. Keeps pots from boiling over The JBK Pot Minder is ideal for reducing those messy boilovers. Simply place the Pot Minder in the bottom of the pot when cooking or warming pasta, soups, potatoes, vegetables, or milk. The unique ceramic material and product design modify bubble formation when boiling begins. The disk also chatters on the bottom of the pot (Boil Alert) as boiling becomes more intense. Your ceramic Pot Minder will help prevent pots from boiling over when cooking. When the water begins to boil, the Pot Minder will begin to chatter in the bottom of the pot. If you prefer, when the Pot Minder begins to chatter, you can remove it and turn the heat down. Approx 1.5” in diameter and .3” thick