The device does what it should: it heats the water and thus the contents of the vial. However, a very large drawback is a lack of timer or at least one temperature reading on the controller: after 3 minutes the ideal temperature of a vial has not been reached, and after 5 minutes it is way too hot. So there remains again the temperature measuring at the wrist, and one always needs a clock and a free hand, so that the vial is taken exactly the right time: cumbersome and not just parents with children ...
