This is a sensational set and while preparing each vial in use! I do not know what I would do without! In the thermos I always boiled, hot water and can thus prepare immediately a Flascherl when our baby is hungry. The water keeps perfectly hot! Also overnight! We have very hard water, resulting in lime attaches easily in the pot after about 1 month. This is very easy with eg organic Schnellentkalker (citric acid granules) remove. Since our baby rarely empties the bottle in a train, but usually takes 20-40 minutes for it in the not kept warm drinking time in plastic cups or again heated to optimal drinking temperature, it should be cooled. For this I empty hot water from the thermos into the plastic cups and put into the bottle. Same thing on the road. Quite simply, so spontaneously somewhere prepare a bottle.