I have had it for about a month. So far it has turned out very good at a very good price. Note that the mechanism also works for other similar heaters.

No matter how many hours it stays, the temperature inside does not drop.. it is really exceptional. Only with a slight hit, the bottom part was slightly damaged and does not fasten 100% well

It is the second Nava thermos that I buy as I was very satisfied with the first one. I use it for water at the beach in the summer and for coffee at work in the winter. In both cases, it keeps the temperature as it is for 9-10 hours (under normal conditions).

I have bought several Nava thermos and they all have rusted and stopped keeping the water hot. Bad product!

We have bought 3 thermos in all the liters that Nava produces in order to put hot water to make baby's milk and all of them have rusted inside and outside. Finally, after a few days or months of use, when you put hot water, it burns externally and stops keeping the water warm.

It needs a little "adjustment" in screwing to avoid leaks.
Otherwise, it is a fairly high-quality construction that does its job correctly and at a very affordable price.

For its price, it is the best for the beach. Don't forget to cover it with a towel when exposed to the sun, better to keep your water/drink cold all day.