Heat sensitive color changing timer monitors egg doneness as the eggs cook, based on the color change. It sits in the pan during cooking and gradually shifts color to indicate firmness from hard to soft. When the eggs are cooked, the timer changes color to reveal readiness. Innovative design provides a simple way to achieve boiled eggs. Easy to use, just pop it in the pan with the eggs. The timer is designed in a cute egg shape and offers a straightforward, visual indicator of doneness. Safe materials: made from food grade unsaturated polyester resin and thermal paper. This construction is intended to be safe for use with food. Grinding marks on the bottom are normal and do not affect the function of the timer. Easy to use: drop the timer into a pot of boiling water. Line markers are visible during cooking. As the egg boils, the color changes so you can clearly see when ready. When the color reaches the scale indicated by the label and the line, remove the eggs from the pot. Use scenarios: In a home kitchen to consistently cook soft, medium, or hard boiled eggs according to preference. For meal prep or batch cooking, enabling you to prepare eggs in advance with reliable doneness. For busy mornings or kids' lunches, providing a clear, quick signal to avoid overcooking or undercooking.