El producto ea muy malo, al 2 dia de uso dejo de funcionar la pantalla y no dura el liquido como lo dicen en la informacion que dan al momento de comprarExcelenteNever keep nothing coldMuy útil, mantiene el té calienteI chose to purchase these thermal flasks because they have a LED temperature display on the lids. Oddly enough, I’m returning the flasks for the same reason. The display doesn’t work as described, as it seems to only work when it wants to which isn’t very often.Would be nice to be able to convert from celsius to fahrenheitCome with the battery already installed, so you will not know how long been since it shipped out off the factory and waiting in the warehouse, Mine stop working little more then one month. Worse, there is no way that battery can be replaced, it sealed good inside the cover. ( I search the net, all said you need to buy a new cover. )Water turn warm after 4-5 hours.The battery on my bottle died a month after purchasing. The LED temperature grew more and more faint over the last week before dying completely yesterday. The bottle does a good job keeping my coffee hot, but the battery that's included must have already been used.