Make sure your baby's milk is not too hot to drink by placing one of these colour changing discs into baby's bottles when making up the feed. They float in the milk and turn from purple to pink at 37'c to show when milk is too hot to drink.The discs are easily washed and sterilised at the same time as the bottles and teats.They come supplied in a useful storage case complete with a food tester and disc retriever which also gives a scald warning indication.