Practical bottle warmer for on the go. can be operated via USB... so in the car or for example. for Powerbank. Different temperatures can be set. Apparently, this is constantly being monitored. The display switches between actual and desired temperature. I checked the set temperature with a thermometer and it matched quite closely. The quality is very good. The bottles fit perfectly. I am positively surprised by the price. The shipping was fast. A great and very practical product.