I tried, unsuccessfully, to unscrew the knob, turning into space for several minutes until finally understand that it is just enough to turn a little bit to bring the liquid to pass. Hard to make it simple actually.
So if, unlike me, your brain is not idle, this product may suit you.
The design is extremely nice.
The product keeps your beverage hot or cold for several hours.
The system, once one has understood, is extremely clever and practical.
