Very good quality.
Keeps hot things hot and cold things cold! With cold water, forgotten inside for 2 days, from beach to beach and it was still cold.
I removed one star due to its size.
Quite bulky for the 750ml quantity it holds. Compared to a Thermos 1200ml that I have, it has almost the same thickness and is only 5cm shorter, with 450ml less than the other.
A bit expensive... I would rate it between 25-30 and not over 40, which is usually its price.
Anyway, if you want quality and don't mind the slightly larger size, get it!

There is no trace of plastic, there are no leaks. It keeps cold and hot for several hours. The only plastic parts are the rubber bands that secure it, which can be removed and cleaned. Replacement rubber bands are available in the market. And if you want, you have the option to disassemble the entire thermos.