The Nuby RapidCool Portable Baby Bottle Maker rapidly cools formula feeds to the perfect temperature, so you can make easy ready-to-serve baby bottles anytime, anywhere!Complying with the NHS guidelines for safe formula preparation, Nuby RapidCool cools formula feeds from boiling to the perfect temperature in as little as 2 minutes*, making it easy to prepare ready-to-serve baby bottles between 90ml (3oz) to 240ml (8oz). The digital display changes colour as the feed cools, then turns green once its ready!Fill your RapidCool with freshly boiled water using the measurement markers inside, add your pre-measured formula powder and mix well. To check your feeds temperature, turn the RapidCool upside-down for 5 - 10 seconds so the formula comes in contact with the thermometer inside the digital lid. Turn the RapidCool upright and tap the display to check if your formula is ready. When the display turns green, pour the feed into a clean and sterilised baby bottle to serve your fresh formula