The Avanti Colour Changing Egg Timer takes the guesswork out of boiling eggs. Being a heat-sensitive timer, it delivers perfect results every time regardless of the number of eggs being boiled or the amount of water being used. To use, simply place the timer along with eggs in a pot of water. As the water boils and the eggs begin to cook, the heat sensitive timer will gradually change colour to indicate on the scale when the eggs are soft, medium or hard boiled.