Place this reusable temperature sensor into your pot with eggs, and the colour will change to indicate when the eggs are soft- or hard-boiled. As the eggs cook, a visual colour change on the graduated scale tells when they are soft, medium or hard by precisely sensing heat instead of time. The sensor accounts for the number of eggs, the amount of water, even the altitude at which the eggs are being cooked. Soft boiled eggs are as you like them, every time. Hard boiled eggs are no longer overcooked, so they have perfectly coloured yolks and a smooth texture.