Of the three in the pack I gave one away so I have no idea how it turned out. If it was anything like the two I kept it's already been thrown away. One worked maybe three-four times and did a great job. After that it wouldn't heat up at all. The other never worked to begin with. Sort of disappointing to be in a hotel room ready for your morning tea and have this water heater do nothing. Absolute junk as far as I'm concerned.
These coils to boil water and food are great, especially for the type of traveling that I do...it is so easy to make coffee and tea at the hotel without having to incur in room service. The package comes with 3. I have used one for my nightly cup of tea and after about 6 days of use the thing is burnt out. I am disappointed but it could be one lemon amongst many so I am going to try the other one. In the meantime I am going to chat with O and ask to have one more delivered to me. Other than this, it is a great product that saves you money if you travel as much as I do.
I can't say myself how they work because I am sending them to soldiers over seas as part of a project I am doing with the American Legion Auxilliary. However, we have gotten good feedback. Many of the soldiers donot have access to hot water so these come in handy when they want to heat something up such as soup or coffee.