Visual display of the degree of hardness: from soft to hard. Place the desired number of eggs together with the EI-ZEIT minute into a saucepan and add cold water. Bring to a boil. Then, at a reduced temperature, let it boil. During the cooking process, the egg timer heats up and changes color from the outside to the inside from light red to dark red.  Product size: 5.8x4.1x3.4 cm Package size: 10.2×3.5×15.8 cm Material: Resin polymer