BrainstreamPiepEi-The Singing Egg Timer for Cooking, Beige with Cockel Design, 5,1 x 4,5 cm

I have had these for many years now. The batteries last for a few years (depending on use). They really work. It is important to keep them in the fridge with your eggs so they have the same temperature when going into the water. You'll first hear a beep to show it's working and then just wait and listen out for the music. First song soft boiled, second medium third hard boiled. Put it in cold water after taking your egg out to stop it playing and save battery life. We tried everything to confuse it from putting eggs in cold to boiling water but it always came up with a perfect soft boiled egg (as long as they go in together being the same temperature)