Place this colour changing egg timer in a pot of water along with your eggs. The timer darkens to indicate levels of doneness: soft, medium or hard. The timer works by absorbing heat, so it doesn't matter if you start with one egg or a dozen, with cold or hot water, at sea-level or a mile high or even how fast your stove heats up. You'll get perfectly boiled eggs to your liking, every time! Constructed of 100% heat resistant, food-safe resin. Calculate precisely by temperature instead of time with this egg timer for easy breakfast, lunch or dinner prep.